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Introduction to Fire Origin and Cause
Terms in this set (279)
Covering footprints or tire marks with ______ to prevent degradation until photos can be taken or casts of the prints can be made.
Closing ________ and other openings to protect any burned papers in stoves, furnaces, or fireplaces.
Storing charred documents in containers such as _______, small _______, or ______ that protect documents from drafts.
In addition to making an initial report, the first responder should take note of the _______, ______, and _______ of potential physical evidence as well as the identity of any victims or witnesses.
Upon arrival, determine the general location of the fire, its ______, flame ______, and where the flames are extending ______ the structure.
Ignitable liquids can be spilled accidentally or used as _______ or _______.
Note any tools such as _______ equipment, pry bars, or screwdrivers found in areas away from workshops.
As first responders, FFs have additional responsibilities at fires including the following: (2)
Making observations about the incident during fire suppression
Protecting indicators of origin and cause during fire supression
The condition of an intrusion system or fire protection system, if present, should be documented, including any deficiencies that may have affected their operation. These deficiencies include shut or partially closed ______, alarms in _______ mode or disconnected, and lack of current inspection and maintenance records.
Flashback, re ignition, several rekindles in the same area, and an increase in the intensity of a fire may indicate _______ use.
Fire patterns- note the fires _____ and _______ patterns. These can trace how the fire spread, identify the original ignition source, and determine the fuels involved.
First responders should not discuss their observations with other responders until after documentation is complete. When members of the same crew discuss events, they tend to come to a consensus about what happened and develop a ________ rather than trusting their individual observations.
Limit or postpone nonessential overhaul operations until the ______ or whoever is in charge of the investigation authorizes it.
Some supervisory personnel, including FD company officers, may have additional responsibilities such as: (5)
Ensuring scene safety
securing the incident scene
initiating the investigation
determining the point of origin and fire cause ***
Completing reports and taking appropriate follow up actions
The emergency response agency, usually the _________, should keep control of the premises and guard the scene until all evidence has been identified, documented, and collected.
In accordance with local policy, the _______ ensures that the PRELIMINARY origin and cause investigation is conducted.
The majority of fires that occur each year in North America are of _______ or ______ origin.
An ________ fire is willfully set under circumstances in which the responsible party knows it should not be ignited.
Who called in the alarm include: (5)
date of birth or other helpful ID info
location of caller
Report forms may be found in NFPA ____. This document contains numerous report forms that may be used for structural, wildland, and vehicle incidents as well as those involving injuries or fatalities.
In the event the responsibility for cause and determination is transferred to a fire investigator, first responders should make their statements only to the _________.
Any public statement regarding the fire cause should be made only after the investigator and ______ have agreed to its accuracy and validity and have given permission for it to be released.
ranking fire officer
The investigation must be free of bias and corroborated by ________ principles within the emergency responder's level of expertise.
When working with an insurance company investigator, first responders must still perform the origin and cause determination in an _________ manner.
The ________ primary responsibility is to determine if the owner's insurance policy will cover the event that caused the damage, and if so, determine the scope and value of the loss.
A _____ adjuster is a person retained by the insured party. Their job is to establish the scope and the value of the loss.
public claims (not the insurance company)
When responding to an emergency, first responders have the right to enter and remain upon the subject premises during the emergency. The emergency creates the ________ that provide responders with the RIGHT OF ENTRY.
In order to remove property that may be relevant to a fire origin and cause investigation, the first responder will require either _______ or a _______.
consent of the owner
NFPA 921 defines _________ as Loss, destruction, or material alteration of an object or document that is evidence or potential evidence in a legal proceeding, by one who has the responsibility for its preservation.
Protective ________, _________ protection, and _________ devices all help to prevent injuries and illnesses resulting from exposure to scene hazards.
Before beginning a fire investigation, an investigator should check in through the accountability system and consult with the safety officer or IC to obtain info concerning site safety and hazards. An investigator should also complete a __________ assessment of his own to corroborate the info learned from the safety officer or IC.
Some incidents may require the use of a ________ structure to ensure that priorities from multiple agencies are considered during the resolution of an incident.
The primary objective of a site safety assessment is to _________ the level of RISK to personnel so that a safe, effective, and timely investigation can be conducted to determine the origin and cause of the incident.
(site safety assessment should be done on all scene regardless of size)
First responders should begin assessing safety upon ARRIVAL. _______ and _______ surveys of the scene will identify most safety hazards.
All structural integrity issues and all collapse hazards must be clearly ________ and ________ BEFORE beginning fire investigation activities.
Protection for the _______ system, _____, ______, ______, and ________ is essential and considered MINIMUM level of protection at any scene.
Concentrations of air contaminants during fire investigation activities typically exceed occupational exposure limits. Because of this, there should be continued monitoring of the ________ conditions and _______ levels at the scene.
Atmospheric and CHEMICAL monitoring devices should be used to verify or to establish the levels of _________ protection required at the scene.
First responders may be exposed to lethal levels of toxic byproducts of combustion during the ______ or ______ stage of a fire while conducting salvage and overhaul ops.
The particular toxic gases that may be found at fire and explosion sites vary according to 4 common factors: (4)
-nature of the combustible
-rate of heating
-temp of the evolved gases
______ should be utilized in atmospheres with CO concentrations above 150 PPM, and ______ MAY be used when CO concentrations are below 150 PPM. Finally, CO concentrations should not be utilized to predict the presence of other __________ found in the overhaul environment.
In areas where debris will be disturbed and dust created, a minimum level of protection such as an ________ respirator and ______ protection should be worn.
Even when an SCBA is not deemed necessary, protection from PARTICULATES is still essential and may be achieved through the use of an ________ with proper FILTERS.
Air purifying respirator (APR)
These dust particles can also be absorbed through the eye. If a half-face mask is used, ________ must also be worn.
Particulate air filters such as ________ or ________ should be the primary filtering media.
-High efficiency particulate (HEPA) filter
-organic vapor/acid gas cartridges
The length of time that filters are useful depends upon the _____ and ____ of the first responder, _____ spent in the environment, and amount of _______ in the environment.
An AIR filter is the primary particulate filter and should be serviceable for several fires depending on the exposure time and particulate present. The primary means of evaluating its serviceability is the ease of difficulty of _________.
The organic vapor/acid gas cartridge is effective for approx. ___ to ____ hours of use. The indicator that it is no longer serviceable is the ability to detect a _____ or _______.
(organic vapor/acid gas cartridge)
These cartridges are sealed and meant to be opened and placed in service at the scene. They are affected by humidity and begin to absorb vapors whether being used or not. For this reason, the cartridge is a ______ item.
Particulates are always present, so at a minimum, wear an APR. APRs should be only used in an atmosphere that is NOT _______.
Immediately dangerous to health and life
The following are some HAZARDS that can be detected using available monitoring detection equipment: (5)
Devices used to detect these hazards (atmospheric) include the following: (5)
-Colorimetric tubes (detector tubes)
-Combustible gas detectors
-Single gas electrochemical sensor detectors
All structural FFing coats and trousers should meet the standards set forth in NFPA ______.
1971 standard on protective ensembles for structural fire fighting and proximity fire gear.
If the preliminary investigation is extended, and burn and impact risks have been minimized or removed, first responders should wear _______ coveralls or trousers and shirts.
Hard hats should meet the requirements of ANSI Standard _____, standard for industrial head protection, and OSHA regs in the US or Canada Center for Occupational Health and Safety in Canada.
(firefighter helmets must meet NFPA 1971)
Eye protection can include ______, _______, and _______. All eye protection must meet the requirements of ANSI standard _____, American National standard for occupational and educational personal eye and face protection devices.
Gloves can protect against extreme temps and provide resistance to ____, _____, and ______.
Normal turnout boots MAY be sufficient for postfire activities. Boots should be _______ and provide adequate ______, ______, and _____ protection.
The boots should protect against ______ and ______ injuries as well as provide extra ankle support to assist while working on uneven terrain.
The ______ virus is particularly threatening because it has been found to live several days in dried blood spills.
Infection control procedures and body-substance isolation require that ALL body fluids be treated as though they are infectious. Wearing disposable _______, ______, ______, and ______ protection is the best way to provide a barrier between the FR and any infectious agent.
Where exposure is likely, such as scenes involving fatalities, ______ mandates establishing a comprehensive protection program.
OSHA (title 29 CFR 1910.1030 bloodborne pathogens)
Always use disposable ______, _______, and ______ when exposed to potentially infectious materials.
There is always a threat of rekindle at a fire scene. First responders must always be aware of ______ from any location within the fireground.
The load-bearing walls of a structure will usually have the ______ length.
To avoid introducing unnecessary tripping hazards, power cords for these units must have proper insulation and highly visible colors such as ______ or ______.
It is also recommended that a _______ be used with portable electric equipment at a fire scene.
ground fault circuit interrupter (GFCI)
As the size and scope of an incident widens, criminal activity may be uncovered and the need to establish a perimeter for personal _______, _______ control, and ______ control becomes more essential.
(perimeter should surround entire scene)
The sewer utility and the local ______ officer must be notified when situations of this type are found.
A secure investigation scene is one with a _________ perimeter and someone to _______ that perimeter.
The perimeter for explosions should be established at _____ times the distance from the FARTHEST piece of debris found.
(can move if debris is found farther afterward)
If the explosion is suspected to be the result of an explosive device such as a bomb or IED, suspend investigative activities, call a bomb squad and ensure the area is checked for _______ devices.
The perimeter should extend beyond the farthest piece of _______ located during the examination of the fire scene.
To be effective, fire-scene perimeter must be both _______ and _______/
To accommodate the rapid establishment of a perimeter that is visible and recognizable, many pub safety organizations use _____, _____, or marked _______.
For long term ops, consider _______ officers and/or the installation of _______ or _______.
__________ is a broad concept, encompassing anything that can TAINT evidence.
________ refers to evidence that is destroyed, damaged, altered, or otherwise not preserved by someone who has the responsibility to preserve it.
Spoliation occurs when the movement, change, or alteration of the evidence prevents another investigator or interested party from obtaining the same _______, _______, or ______ value from the evidence as the initial investigator.
Preservation of evidence starts at the time of the initial _______ and may include the entire fire scene.
Evidence can take many forms such as: (3)
-Observations of witnesses
-Statements from building occupants or from FFs who fought the fire
-Record and documents obtained after the fire
Broadly speaking, evidence is any data that may be used to prove or disprove a certain _______.
Three primary classifications of evidence are
Circumstantial evidence can consists of ______ evidence.
________ evidence is composed of facts to which a person can attest without further support. This evidence is found through the five PHYSICAL senses.
(smelling odors, seeing someone pouring gas ect)
_________ evidence supports an inference formed from direct evidence.
More than one _________ can be drawn from circumstantial evidence. For example, the person running from the fire may have set the fire or may be fleeing for safety.
A common misconception concerning circumstantial evidence is that it is not as valuable as ________ evidence.
(circumstantial evidence is heavily relied on in criminal and civil litigation as well as fire investigations)
Additionally, most fire investigations rely heavily upon circumstantial evidence. Fire investigators don't often see the fire, so they must draw ________ from __________ of the effects of the fire. For ex, a fire investigator sees charring on wooden furniture, assumes the furniture was not charred before the fire, and therefore infers it was damaged by this fire.
_________ evidence includes physical objects available for inspection.
Some physical evidence found at the fire scene may be better described as ________ or _________ trace evidence.
biological or non-biological
Step 1 to preserving, collecting, and documenting evidence:
Secure the scene and keep unnecessary people out of the area.
Step 2 to preserving, collecting, and documenting evidence:
Preserve the evidence that is in danger of destruction in the best possible way
Step 3 to preserving, collecting, and documenting evidence:
Photograph the evidence in place. In addition, mark, label, and document the location of the evidence on the fire scene sketch.
Step 4 to preserving, collecting, and documenting evidence:
Note the time the evidence was discovered, where is was discovered, and the name of the person who made the discovery.
Step 5 to preserving, collecting, and documenting evidence:
Maintain and secure the area against unauthorized entry, including other first responders, while the evidence is in its original position or until it is collected. (once moved, record time and name of person moving it)
Maintaining the _______ of evidence is essential if evidence is to be admitted into evidence during a trial.
chain of custody
Anytime the custody of an item changes, the following info should be obtained: (4)
-Name and contact info of the current and prior custodian
-date and time that the item was transferred and its new location
-description of any modification, handling, testing, or other alteration that occurred while the item was in the custody of the current custodian
-condition of the item or its packaging when it was transferred to the new custodian
Chain-of-custody issues extend beyond the physical evidence collected at a fire scene. ALL incident related evidence including documents of ___________ value, and any other items that support the findings of the investigation are also subject to chain-of-custody rules.
If FRs must move an object of evidence, they should _________ it, document its ________ and ________, and ______ it before it is moved.
(evidence should only be moved to protect it from damage)
The ultimate objective of evidence collection is to preserve artifacts so they retain their _______ value and can be analyzed using the _______ method, and if necessary, unltimately be _______ in the court of law.
__________ by personnel on the scene, for example, tracking ignitable liquid residue on boots from one room to another.
A major concern with regard to tools and equipment used in the collection of PHYSICAL evidence is the prevention of cross-contamination of evidence that will be subjected to analysis for _______ evidence in a lab.
Another potential source of contamination are FFing gloves, which should NOT be used while collecting samples. During the actual collection process, a pair of ___________ gloves should be used.
unused disposable exam
(put on right before collecting, should not be placed in container with material, number the gloves and container for each sample sequentially, and photograph gloves by sealed container at location)
After fire-suppression operations are completed, document where this type of equipment was used and whether it was ______ while it was in place.
Exhaust fumes from the power equipment blowing into the scene may also cause contamination. Document the following about power equip fumes: (4)
-method used by the equip to exhaust fumes
-number of hours the equip was operated
-location of the equip at the scene and its proximity to building openings
______ should collect and tag all evidence.
Pieces of glass or bottles.
-Pick up broken glass to save potential fingerprints. When picking up glass, place two fingers at the ______ of the glass.
-Pick up a bottle by __________ into the neck or by gripping the upper extremity of the neck
-Put glass exhibits in warm, dry place, and stand them ________.
-Do NOT wrap the object in a _______- any fingerprints will be smudged.
- Use ______ bags or envelopes for storage
-inserting a finger
Ash and common fire debris
Seal ash and other debris in an unused, airtight _______ can or ______ container.
The heat of a fire does not necessarily destroy fingerprints.
Handle the containers only on the ______ or _______. Seal these containers in ______ or ______ containers.
-Place liquid samples into clean, unused _____ cans, glass ______, or special evidence ______.
-Do not use ordinary plastic containers that have plastic lids
- After collecting a liquid sample, place a clean, unused _______ or other approved sample collection material from the same box into an empty container, and then seal and label. The testing lab will use this container as the ________ sample to prove that there was not contamination of the other containers.
Materials saturated with liquid.
- Place in proper container
- Do not overlook items such as concrete and soil as possible sample materials because they may also absorb ignitable liquids. Wood can also be taken as a sample but may no be as absorbent as some other materials. Wood from protected areas, such as _______ between floorboards or behind _______, may be a better sample source.
- Collect a sample from a clean, undamaged, uncontaminated location of the SAME carpet, cloth, or collected evidence material for testing as a background to show that no contamination was present prior to the incident. This may be used as a _______ sample.
- Leave charred docs found in containers such as wastebaskets, small file cabinets, and binders that can be moved easily
-Handle loose charred docs very carefully, and keep away from _______.
Tire tracks or footprints
-Photograph from several angles, using side _______. Place a _______ beside the tire tracks or footprints to show size relationship. Include a general photograph of the print showing its ________ in relation to the rest of the area.
- If casts are to be made of track, protect the tracks with ______ or large _______ until molds are completed.
Documentation can include: (5)
According to NFPA 921, a _______ sketch is the minimum drawing that needs to be developed as part of EVERY investigation.
(sketches do not have to be to scale but it must be noted " NOT DRAWN TO SCALE")
Using high quality equip or computers to generate drawings, diagrams, or maps for the investigative report will only be successful if details and accurate info are collected during the ________.
scene examination (all specialized artwork based on basic sketches)
Field notes and sketches of the fire scene provide important context of the documentation process, while PHOTOGRAPHS provide exact representations of the ___________.
To document a fire scene, begin photographing on the ________of the building.
(all corners, sides, apparatus routes, entrances, utilities, landmarks)
Photographs of the interior should include both _______ and ________ areas of the scene.
Recordings from _______ cameras will show investigators how compartments existed when first encountered by suppression forces.
The ________ is defined as the room or area where a fire BEGAN
area of origin
The _________ is the EXACT physical location where a heat source and fuel came into contact with each other and a fire begins.
point of origin
The data gathered during the systemic evaluation of the fire scene is analyzed using the _________ method.
This process begins when the emergency call is _________ and continues throughout the incident and the investigation.
Often the ______ of origin is readily apparent. If it is not, investigators should use a methodology that typically involves working from the _______ damaged area to the ________ damaged area, although it is important NOT to assume that the area of ________ damage is the origin of the fire.
If a public sector investigator determines the origin or cause of the fire prior to examining areas of the fire scene remote from the origin, their legal ability to examine these other areas may be prohibited. A ________ may be required to continue their scene examination.
criminal search warrant
(determining the area of origin)
Examine the EXTERIOR of structure or vehicle and surrounding area. During a wildland FI, start the examination at the OUTSIDE EDGES of the burned area and work inward
(determining the area of origin)
Examine the interior of the structure or vehicle
(determining the area of origin)
Interview witnesses and other first responders
(may be beneficial to conduct interview before examining fire scene)
(determining the area of origin)
Analyze the info gathered using the scientific method
The examination of a structure fire should start with an assessment of the entire incident scene in order to determine its size and scope. This preliminary scene assessment should begin with the exterior of the structure and continue, if possible, completely _______ the entire incident scene, including the ______.
All points of low burning should be carefully examined. These patterns may be the result of ________ that drops from the building and causes a secondary ignition or they may be an indicator of an exterior _____ of origin.
Fire and products of combustion, __________ efforts, and ________ from the interior of the building or from ignition points on the outside can all cause exterior fire damage.
The patterns found during the interior examination represent the ______ of the fire from ignition to extinguishment.
Part of fire pattern analysis is determining the ______ in which the patterns were created. The goal of analyzing fire patterns is to determine fire spread from the fires ______ of origin.
NFPA 921, Guide for Fire and Explosion Investigations, describes fire patterns as the _______ or ________ physical effects that remain after a fire.
Fire patterns are formed on interior surfaces of a structure as a result of direct flame contact or exposure heat. _________, _________, or ________ can be the heat transfer method that causes a fire pattern.
When examining fire patterns, invesigators should consider at what point in TIME the fire pattern was developed. For ex, a _____ shaped pattern may have been made during the incipient phase of the fire.
On noncombustible surfaces such as brick, plaster, or metals, the patterns may cause surface _______, ______, _______, or ________/
Early in the development of an incipient fire, a _______ shaped plume of hot gas begins to form above the flames.
Plume-generated patterns are categorized according to their geometrical shapes. As the cone of the plume intersects walls and ceilings, it leaves lines of demarcation in various shapes such as ____ or _____.
When there is no apparent fuel package, plume patterns may occur as a result of combustion in the _________.
hot gas layer
As a fire develops next to a VERTICAL surface, the flames and hot gases cause a ____ shaped pattern on the surface. It is one of the most commonly found patterns.
There are two factors that contribute to the shape of the V pattern:
1. The _______ of the burning fuel packages plume from the vertical surface on which the pattern appears.
2. The _______ of the ceiling or closest intersecting ________ surface.
The closer the fuel package is to the vertical surface, the more _______ angled the lines of demarcation are likely to appear.
The width of the V is a function of the size of the _______ that creates the plume.
(waste basket next to wall will have narrow pattern, sofa next to wall pattern will be wide)
U-shaped patterns are closely related to V patterns; however, U-patterns appear _______ on vertical surfaces.
___ patterns appear when the fires flame zone is FARTHER away from the vertical surface.
_______ patterns are commonly found when fires burn immediately next to a vertical surface and the generated plume comes into contact with a horizontal surface that causes the hot gases to spread.
(indicated fire was very close to a wall)
The height of the inverted V is determined by the ______ height the fuel package generates.
________ shaped patterns appear on the undersides of horizontal surfaces such as ceilings or tables.
(appear directly above a fire assuming no ventilation acted upon it)
The ________ of the circular-shaped pattern should show greater damage from the fire (greater depth of char) or other measurable damage effects.
When the fire in question is very small or has a low heat release rate, an _______ pattern can be created if the fire is near a vertical surface of wall.
(also formed when fuel is extinguished or short lived before flame height could reach ceiling)
Fires involving fuel gases such as propane or natural gas can also create _______ patterns.
(flames could escape through the corner created by floor and wall and will NOT likely reach the CEILING ***)
Radiant energy can form patterns on exposed surfaces when compartment fires are extinguished just before FLASHOVER. These _________ patterns may be located on horizontal surfaces such as floors and exposed surfaces of contents located in the compartment.
(non-exposed surfaces usually not damaged)
When hot gases flow over vertical surfaces such as walls and open doors, the heat energy in the gas layer is transferred to the surface through the process of _________.
One type of ______ pattern is the damage that results when air flows over glowing embers on a combustible floor surface which could result in a hole being burned in or through the floor.
Ventilation-generated patterns are also observed on and around _______ and _______ of compartments involved in fire.
doors (hot gas layer fills whole room patterns can be seen from top and bottom of door)
Any time a gas flows through a restricted opening, its ________ is increased.
Combustion occurs at locations where the flammable limits are met, which will typically be the areas of open ventilation. This ventilation pattern occurs where NO fuel package appears to be present. Therefore, the greatest area of structural damage may be related solely to _________.
NOTE: Fire suppression activities can generate patterns from water streams and ventilation. Its called:
The _______ of fuel in the compartment, how the fuel is _______, and the available _______ determine the extent of the destruction.
________ patterns are found on Noncombustible surfaces where there has been direct flame contact or intense radiant heat on the surface.
It is common to find a clean-burn pattern (inverted V) indicating the flame area at the base of an ________ pattern created by a plume on noncombustible wall surface.
When structural components such as wood studs or trim are exposed to flame, the sharp edges of the component are often burned away on the side of the component that FACES the heat source. The result is a pattern that indicated the location of the heat source, commonly known as a _______ pattern.
(Make sure damage is from fire and not suppression efforts.)
When the component is part of a series such as wall studs, the length of the remaining studs also point to the source of the heat, with the ________ remaining stud indicating the most severe exposure.
Irregularly shaped patterns on floors are common. These patterns are often ______ or ______ shaped patterns on the surface of the floor covering. The lines of demarcation observed with these patterns depend on the _______ on which the pattern was formed.
(trailers and doughnut-shaped are easiest to identify)
Because there are a number of ways that irregular patterns on floors can be formed, first responders are cautioned NOT to draw any quick conclusions. _______ testing is necessary to determine if any ignitable liquid caused these irregular patterns.
A trailer of ignitable liquid or solid fuels causes a special type of ________ pattern.
(trailers may appear to be linear on horizontal surfaces)
When ignitable liquids are used to form a trailer on a porous surface, the FR may also observe a ______ effect at the EDGES of the pattern. This occurs when the material on which the ignitable liquid is poured ________ some of the liquid.
A _______ shaped pattern is formed when a pool of liquid is ignited on a floor surface. The pooled liquid actually keeps the surface beneath it COOL as it burns.
(demarcation will be on edges and little damage in center portion)
_______ are most commonly found on the top edges of floor joists.
_________ patterns typically result from an intense fire burning downward through the floor surface above the joist.
(show deep localized charring)
The following are common causes and locations for saddle burns: (6)
-large fuel packages
-presence of ignitable liquids
-pooling of polyurethane foam from furniture located above the burn
-Burning asphalt shingles(wood roof trusses)
-***LIGHTNING STRIKES to a cable in the attic(ceiling joists)
During scene reconstruction, investigators can use _________ areas to place the contents back into their locations at the time of the fire.
Uniform charring on an item indicates heat ______ from both the areas above and below the item.
Sometimes an object blocks a fire's radiant heat from reaching a combustible surface behind the object. The pattern formed from this phenomenon is known as _________ and can obscure other patterns in the shadowed area.
Heat shadowing (often found alongside protected areas)
The area of origin is a _______ that must be tested.
Ventilation can also force trapped, unburned products of combustion outside the compartment through duct systems, broken windows, or open doors. These products of combustion may generate fire patterns outside the compartment, and the patterns should be interpreted as?
Originating in the compartment rather than as a separate fire on the exterior of a structure or in another compartment
When a room has been subjected to a flashover or has transitioned to a full-room involvement, many patterns that might have been visible before flashover or full-room involvement may no longer be readily visible. However, a FI can use depth of _______ or depth of ________ analysis to determine where earlier fire patterns were before the room reached full involvement.
_________ patterns result from the application of heat, flame, and smoke, which are produced as a result of the fire's growth and spread from the INITIAL heat source.
A fire plume's flame and hot-gas zones produce INTENSITY patterns. Intensity patterns leave their physical marks such as lines of ______, surface _______, or ________ marks on a surface.
Proper analysis of intensity patterns assists in determining the ______ of the fuel package that produced them.
Each fire pattern found at a scene is the product of an individual fuel source. Understanding the ________ in which those fuels ignited can lead to the area of origin.
Today's passenger vehicles may have additional fuel loads and ________ than older model vehicles.
competent ignition sources (for ex. vehicle electrical system)
(produces enough heat to raise a fuel to its ignition temp)
________- On some newer cars, these may explode if they are cut due to the presence of supplemental restraint systems.
Roof support posts
The vehicle fire scene can be divided into three areas for examination:
The _______ around the vehicle
The _______ of the vehicle
The _______ of the vehicle
When examining the interior of the vehicle, areas for exam can be further divided in separate compartments as follows to make documentation and comparative analysis easier: (3)
Passenger compartment (this can be further subdivided such as drivers side, rear ect)
While conducting a vehicle FI, one of the first steps is to obtain info regarding the vehicle's ______ BEFORE and DURING the fire.
Two methods of identifying the vehicle should be made: confirming the ______ attached to the vehicle and obtaining the ______ from the vehicle.
VIN (cars after 1981 contain 17 characters)
( do not contain letters I, O, and Q. will have numbers 1 and 0)
______ character is a check digit used to verify the ACCURACY of the VIN.
The VIN or partial VIN may be located in several different areas on the vehicle. The following is a partial list of areas where a VIN may be located:
- On the _______ side of the dash
- on a combustible label on the drivers ________.
- On a combustible label on the underside of the ________ cover
-Stamped on the ________ in the engine compartment.
Additional methods of positively ID'ing the vehicle may be obtained from ______ stickers or manufacturer _______ information labels, manufacturer ________ control labels, and vehicle ________ information labels.
undamaged vehicle of same make, model and year)
(could provide misleading info to burned up car investigation)
Determining the REST angle will assist in understanding the fire patterns. Determination of the vehicle's rest angle may be conducted by examining such things as __________.
(titling vehicle until Al is plumb will give angle of the vehicle when on fire)
_______ fire patterns show movement on the vehicle's body panels such as the hood, fenders, doors, roof, and trunk. These fire patterns may appear as ________ extending from a particular compartment as the fire progresses across the vehicle body panels.
The exterior of the vehicle may reveal fire patterns on the _____ panels and _______.
(take pics of top, undercarriage, each wheel, and each panel)
The exterior documentation of the vehicle should include the following:
-tire type, condition, size, tread, wheel condiditon
-door position (open/closed or locked)
-Window position- (broken, up, down, condition)
-Fire or nonfire damage to each body panel
-fire debris from vehicle to ground
Investigators should remember that an engine compartment fire may spread into the passenger compartment through pre-existing holes in the _______.
(fire can spread from interior to engine comp. through same holes but slower)
Damage to the ______ portion of the windshield indicates directional fire spread from the engine to the passenger compartment.
As the fire plume develops and impacts the combustible head liner a _________ is formed which will affect the TOP portion of the window.
The temp of exhaust systems may _______ substantially for the first few minutes after a vehicle has been shut OFF.
Documentation of the CARGO compartment should include following: (5)
-damage to interior of compartment
-documentation of personal effects with their condition
-damage to spare tire
-damage to wiring
-fire pattern analysis
Documentation of the passenger compartment should include : (5)
- Fire pattern analysis
- Condition and position of switches, handles, levers
- missing or aftermarket components and condition
-documentation of personal effects with location and damage
- doc of vehicle wiring
_____, ______, ______, and _______ variations all affect the fire's spread rate and direction of travel.
aspect (direction in which slope faces)
The area of origin may display evidence of _______ and _______ intense fire growth than at the head or leading edge of the fire.
(more unburned fuel left in area of origin)
White ash is a product of more complete combustion, and it appears on the ________ sides of the remaining debris.
During the interviews, the investigator will be looking for pertinent info that consists of these (6). These are the six basic questions that should be asked of EVERY witness.
As part of the analysis of fire damage, ________ may be used to show the direction of heat or flame spread using arrows on a floor plan of the room or structure. One method is to use arrows to point from the areas of _______ damage to the area of the _______ damage.
vector diagrams (directs to area that burned most intensely)
The vector diagram is most useful when drawn on a copy of a diagram showing the _______ condition of the room or area.
The solid by-product of burning wood is referred to as ______, and its DEPTH is a key piece of evidence that an investigator should examine when attempting to determine how a fire ________.
Depth of char is NOT a reliable indicator of specific fire ________.
When gypsum wallboard is exposed to heat, moisture embedded in the board evaporates and provides fire resistance. This process and the damage it leaves behind are both known as ________.
(wet wallboard yields no reliable measurement)
The ultimate outcome of depth-of-calcination analysis, as with depth of char, is an objective and measurable determination of the ________ or ________ of a fire.
Simply stated, an _______ or ________ is a visual documentation of the path of electrical arcs at a scene.
The arcs are surveyed and mapped based upon the damage left on _________ such as appliance cords, wall conduits, outlets, or junction boxes.
The term _______ can be defined as the sequence of events that allows the source of ignition and the fuel to come together.
Once the origin is identified, the investigator should look for heat sources which might be potential sources of ignition. A competent ignition source must have the following three qualities:
1. Sufficient ________ to ignite the first material
2. Sufficient heat energy ________ to result in the ignition
3. Sufficient ______ to transfer the required heat
For solid fuels, the ignition source must have the potential to supply enough energy over a period of time to cause ________ of the fuel and provide sufficient ________ to ignite the resulting flammable VAPORS.
Liquid fuels require a heat source that provides sufficient energy to cause the liquid to change state from liquid to vapor. A heat source with _________ is then required to cause ignition for the vapors.
minimum ignition energy
________ fuels require the least amount of energy for ignition because there is no energy required to change the fuel's physical state before ignition.
A flaming wood ember could reach temperatures of approximately ________F.
(distance of ember traveled should be evaluated because ember loses energy as it travels.)
If the outside fire is close to the POINT of origin, the possibility of a burning ember serving as a competent ignition source exists. In this case, the type of heat transfer would be _______, while the method of ignition would be _________.
During welding and cutting ops using a gas-fueled torch, two sides of the fire tetrahedron, ______ and ________, are present throughout the process.
NFPA 51B, standard for fire prevention during welding, cutting and other hot work, requires that an area of _____ feet around the operation be free of combustibles (or combustibles be covered with flame-resistant materials or guards). In addition, a fire watch must be posted for at least ______ minutes after the operation is completed.
The potential for drops of solder to ignite combustibles is low as the melting temp of the material is in the _____F to ______F range which is below the ignition temp of wood.
Heat from pilot lights and fuel-fired equipment is also a common source of ignition for fires. To make a determination that a fire was ignited from this type of source, the investigator should consider the _________ of the fuel first ignited and the method of heat _______ from the source to the fuel.
Heat sources from _____ fuel-powered equipment include wood and coal heating equip, the chimneys servicing those devices, and sparks or embers escaping from the device or chimney. (these devices are potential sources of ignition by conduction)
Use of the wrong fuel may cause overheating of the appliance and/or failure of the appliance particularly at the _______ where the equip can transfer heat to surrounding combustible surfaces.
The first responsibility in the examination of electrical wiring or equipment located near the area of origin is to determine if they were _______ at the time of the fire.
Electrical wiring ignition source
In making a final determination, the investigator should note the _________ of the distortion or damage as it relates to the _________ of the suspected origin.
(location more important than type of damage which needs forensic experts)
The aluminum and heated copper alloy at the copper surface form a material that has a lower melting point that either aluminum or copper. Severed branch circuit conductors that have a silvery appearance most likely have been subjected to this ___________, not electrical arcing.
(pot metals- zinc, copper, aluminum. metals that have low melting point)
A 100 foot heavy duty extension cord may be capable of safely providing electrical energy to a window AC as long as it is fully EXTENDED. The same cord tightly coiled on the floor near an upholstered chair could generate sufficient energy to both damage the extension cords insulation and pyrolyze the fabric. Melting of the insulation may occur during an _________ condition as the conductor experiences an increase in heat.
Arcing of the conductors through _______ is also possible.
char (of insulation)
A ___________ is an abnormal path of current in a circuit that normally leads to an overcurrent condition.
If the short circuit is the result of contact between metal objects that are normally insulated from one another, the heat produced by the overcurrent could increase to the point that metal is melted. If the metal is heated to the point that it is vaporized, an _____ occurs.
(molten droplets are released and could ignite fuel)
(copper droplets cool fast, aluminum do not cool fast)
The most common cause of electrical fires is ________ of electrical equipment. The second most common cause is poor electrical _________.
The flow of current through a conductor normally produces some heat due to the resistance of the material used to form the conductor, called __________.
If the surface of an aluminum conductor is exposed to air, a high resistance OXIDE forms. Aluminum connection exposed to air are usually treated with a _______ chemical to prevent oxide formations. Current flow through the oxide layer causes resistance, resulting in localized but very ______ temps.
An incandescent light bulb can generate surface temps of up to approximately ______F. The surface temp of an incandescent bulb depends on its _______ and ______.
(if bulb is insulated, wrapped in bedding or towel it can ignite it. bulb itself is usually not a competent ign source)
High intensity lamps that use quartz halogen bulbs are competent ignition source because the bulbs used will generate surface temps of up to _______F.
_______ lamps operate under high pressures and temperatures (1832F)
During the debris removal process, the FI examining the point of origin of a fire suspected of being ignited by explosives or fireworks should attempt to locate any __________.
(incendiary device samples should be taken for lab testing)
A cigarette ember can generate temps from _____f to ______f while free burning. When air is drawn through the cig, temps generated could be as high as _____f. A lit cig placed on a combustible surface will typically only SCORCH the surface.
(if cig is insulated under sheet or in between cushions, it can ignite)
Smoking materials include: (4)
__________ cigarettes are designed to self-extinguish before they generate enough heat to start a fire; however, they can still be competent ignition sources.
Fire standard compliant
Where candles are involved in the ignition, the _____ remnants, _____ remnants, a metal _____, or broken remains of glass candle holder may be found at or near the point of origin.
Ignition scenarios, although relatively rare, occur in nature and require no human assistance. Sources of heat energy in this category include the following: (4)
-heat from the sun
________ is a process through which an organic material increases in temps without an external source of heat energy.
(heating from chemical or bacterial action)
Spontaneous heating is the result of the _________ of a material and the generation of heat as a result of that process.
The following factors influence whether or not self-heating will result in ignition of combustibles:
-rate of heat ________.
-Effects of ________
-__________ properties of the immediate surroundings.
generation(must reheat faster than heat dissipates)
ventilation(enough O2 but not enough to dissipate through convection)
__________ is a natural static discharge that is capable of delivering very high level of electrical energy to localized areas.
As a lightning bolt travels along a conductive path, it may _________ as additional conductive paths are encountered. For ex, a lightning bolt may travel from the electrical wiring to a buildings plumbing system if the pipes are used as a _______ for the electrical system.
__________ is a term used to describe electricity that accumulates on the surface of an object. A body or object with an accumulation of electrical energy is said to be __________.
Charged (positively or negatively)
(Read paragraph a few times to fully understand)
For ignition to occur as a result of a static discharge, the following conditions must be fulfilled:
- An electrostatic charge must be _________
- An electrostatic charge must be __________
- A discharge of sufficient ________ to cause ignition of fuel must exist
- An ignitable mixture of fuel at the _______ must exist
The types of fuels that are most susceptible to ignition from static include the following:
-Solid fuels with a high _________ ratio.
A key component in making a fire cause determination is identifying the material first ignited. The first material must have the following 3 characteristics that parallel the characteristics of the ignition source:
1- Capable of being _________ by ignition source
2- ______ enough to the ignition source to receive energy
3- Capable of ______ and retaining sufficient heat energy
The ________ sequence is the sequence of events that allows a competent ignition source to ignite a fuel package.
(important to develop a series of hypotheses and ask questions to test each one)
When evaluating ignition sequences, investigators may need to consider whether someone's________ or _________ was one of the events that brought together the competent ignition source with the first material ignited.
________- Fires that do no involve a deliberate human act to ignite or spread the fire into an area where the fire should not be.
________- Fires, such as those caused by lightning, storms, or floods, where human intervention has not been involved in the ignition process.
________- A fire deliberately set under circumstances in which the responsible party knows that the fire should not be ignited.
_______- The classification used when the specific cause has not been determined due to a reasonable degree of PROBABILTY.
The terms fire cause and fire cause classification are believed to be interchangeable though they are not. For ex, an investigator has to consider ________ when categorizing or classifying a fire as either accidental or incendiary.
In order to identify a suspect during the investigation of an intentional fire, investigators need to identify and individual or individuals who had both a _______ to commit the arson and the ______ to do so.
Fires set because of personal or professional vendettas fall into the largest category of arson fires and account for _____ % of the total arson problem.
(personal property is target, ignitable liquids SELDOM used, but Molotov cocktails or firebombs may be used)
_________ fires are usually set by two or more individuals for no apparent reason. Schools are prime targets, and other common locations include vacant buildings, trash containers, and vegetation.
Monetary gain is the primary motivator for this type of incendiary fire, and TOTAL destruction of property is the ultimate goal. Firesetters motivated by this attempt to cause the most possible damage in the least possible amount of time.
(ignitable liquids common)
The attempt to cover a __________ is most common with the fire set at the location where evidence, such as fingerprints or blood, was believed to be left. Usually the location is at the point of ______ or where an item has been removed.
(ignitable liquids rarely used)
_________ concealment fires often involve the use of ignitable liquids in an attempt to destroy the body and the evidence of the manner and cause of death.
_________ fires are set to erase or destroy a "paper trail", therefore, the paperwork and surrounding area are the origin for the fire.
(paperwork with ignitable liquids used)
The spur-of-the-moment fires develop as a recognizable ______ over a period of time
Most excitement fires are set during the hours of _______.
Simply stated, _________ means a suspect was capable of setting the fire at the time and place where the fire was set or of procuring another individual to set the fire for them.
Any atmosphere containing less than ____ percent oxygen is Oxygen-Deficient.
At least ____ percent oxygen is needed for flame production and human life.
Physical Evidence is also known as _____ ____ and includes physical objects available for inspection.
In its publication Crime in the United States, Uniform Crime Reports, the FBI statistics show that in 1995, arrestees under age 18 accounted for ____ percent of all arson arrests.
THIS SET IS OFTEN IN FOLDERS WITH...
IFSTA Fire Origin and Cause 4th Edition
Fire Origin Cause and Determination
Introduction to Fire Origin and Cause
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