On October 7, 1963, in Ipatinga—then a village belonging to Coronel Fabriciano in the Brazilian state of Minas Gerais—military police officers opened fire on a crowd of striking steel workers employed by Usiminas. The confrontation followed weeks of tension over working conditions, degrading security searches, and suppression of union organizing at the recently opened steel plant, which employed about fifteen thousand people under harsh and often dangerous conditions.
The immediate trigger was a heavy search of workers leaving the night shift on October 6, 1963, during which food and milk they customarily brought home were confiscated or spilled. This provoked confrontations between workers and police that night in the Santa Monica lodge (now the Horto neighborhood), resulting in beatings, home invasions, shootings, and roughly three hundred arrests. Father Avelino Marques, a local priest, helped negotiate the release of detainees and arranged a morning meeting between Usiminas management, police, and worker representatives, including union president Geraldo Ribeiro.
On the morning of October 7, about six thousand striking workers gathered outside the Usiminas gate awaiting the outcome of that meeting, which concluded around 9:15 a.m. with an agreement to suspend cavalry policing pending an investigation into the prior night's violence. As armed police remained on site despite the agreement, tensions rose, with workers throwing stones and jeering. As Father Avelino and Geraldo Ribeiro were preparing to address the crowd, nineteen military police officers positioned atop a truck began firing into the crowd. The shooting lasted approximately fifteen minutes. José Isabel do Nascimento, a foreman who had been photographing the crowd and was seen firing a revolver at police, was shot and later died on October 17. A three-month-old girl, Ângela Eliane Martins, was killed while being carried by her mother toward the company's medical clinic. Five other industrial workers and a tailor were also among the eight officially recorded dead; 79 were officially recorded as wounded.
The official death toll has been repeatedly disputed, with various witnesses, family members, and later accounts citing figures far higher—ranging from around thirty to as many as eighty deaths—including claims of bodies dumped in the Ipanema river and discrepancies in numbers of coffins ordered locally versus reportedly requested from Belo Horizonte.
In the aftermath, wage increases and changes to Usiminas' security staff followed, along with an initial conviction of the police officers involved. However, the 1964 Brazilian military coup that deposed President João Goulart led to the imprisonment of local union leaders and, on March 8, 1965, the acquittal of the police officers on grounds of self-defense; a military prosecution appeal was rejected in December 1965. Compensation to victims' families did not begin until 2004, following a 1995 law and a 2004 provisional measure covering deaths in public demonstrations. In 2013, on the fiftieth anniversary, survivors and relatives testified before Brazil's National Truth Commission, which in a December 2014 report named three victims and identified the state governor at the time as responsible for the police action.