In February 1980, inmates at the Penitentiary of New Mexico south of Santa Fe seized control of the prison for about 36 hours in what is widely regarded as the most violent prison riot in United States history. They took twelve officers hostage, killed thirty-three prisoners, and injured hundreds, though no hostages died. The uprising followed years of worsening conditions, including overcrowding, unsanitary housing, poor food, cut programs, staff shortages, weak security, and violence fed by the prison’s use of informants. The worst killings occurred in Cell Block 4, and the riot became a lasting symbol of the consequences of neglect and abusive prison administration.