Labor disorders had broken out and on May 4 1886, the Chicago police advanced on a protest; alleged brutalities by the authorities. Suddenly a dynamite bomb was thrown that killed or injured dozens, including police. It is still unknown today who set off the bomb, but following the hysteria, eight anarchists (possibly innocent) were rounded up. Because they preached "incendiary doctrines," they could be charged with conspiracy. Five were sentenced to death, one of which committed suicide; the other three were given stiff prison terms. Six years later, a newly elected Illinois governor recognized this gross injustice and pardoned the three survivors. Nevertheless, the Knights of Labor were toast: they became (incorrectly )associated with anarchy and all following strike efforts failed.