Quote from TIME:

Quinn was one of 43 men (11 guards and 32 convicts) who died as a result of the four-day riot in September 1971—most of them shot by state police when they stormed the maximum-security prison in upstate New York behind a fusillade of bullets.

Now here's what I found after looking up the incident on Wikipedia. Attica, it turns out, was somewhat like the seventies version of Guantanamo Bay:

The Attica Prison riot occurred at the Attica Correctional Facility in Attica, New York, United States in 1971. The riot was based in part upon prisoners' demands for better living conditions. At the time, inmates were given one shower per week and one roll of toilet paper per month. On September 9, 1971, responding to the death of prisoner George Jackson, a black radical prisoner who had been shot to death by corrections officers in California's San Quentin Prison on August 21 while armed and attempting to escape, about 1,000 of the prison's approximately 2,200 prisoners rioted and seized control of the prison, taking thirty-three correction officers hostage. The State began negotiating with the prisoners.

During the following four days of negotiations, authorities agreed to 28 of the prisoners' demands, but would not agree to demands for complete amnesty from criminal prosecution for the prison takeover, or for the removal of Attica's superintendent. Under order of then Governor Nelson Rockefeller, state police took back control of the prison. When the uprising was over at least 39 people were dead, including ten correction officers and civilian employees.

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At approximately 8:20 A.M. on Thursday, September 9, 1971, 5 Company lined up for roll-call. Hearing rumors that one of their companions was to remain in his cell and that he was to be tortured after being isolated for an incident involving an assault with a prison officer, a small group of 5 Company prisoners protested that they, too, would be locked up, and began walking back towards their cells.

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Complaints led to anger when the rookie correctional officer tried to calm the mob of prisoners. He was assaulted and the riot began.

Officer Quinn in the central control room of the tunnels tried to phone for help when he saw what was happening in the tunnel. However, he kept getting a busy signal and the mob of prisoners managed to get into the control room and beat him unconscious with the lead handle of the rotary phone. This officer would later die from injuries received at the hands of the inmates.

The inmates quickly gained control of sections, D-yard, two tunnels, and the central control room, Time Square. Inmates took forty-two officers and civilians hostage and aired a list of grievances, demanding their needs be met before their surrender. In a facility designed to hold 1,200 inmates and actually housing 2,225, theirs was a substantial list. They felt that they had been illegally denied rights and conditions to which they were entitled, illustrated by such practices as being allowed only one shower per week and one roll of toilet paper per person per month.

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The situation may have been further complicated by then-Governor Nelson Rockefeller’s refusal to come to the scene of the riot and meet with the inmates, although some later evaluations of the incident would postulate that his absence from the scene actually prevented the situation from deteriorating. Negotiations broke down and Oswald told the inmates that he was unable to negotiate with them anymore and ordered that they must give themselves up. Oswald later called Governor Rockefeller and again begged him to come to the prison to calm the riot. After the governor's refusal, Oswald stated that he would order the State Police to retake the facility by force. Rockefeller agreed with Oswald's decision. This agreement would be later criticized by a commission created by Rockefeller to study the riot and the aftermath.

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At 9:46 A.M. on Monday, September 13, 1971 tear gas was dropped into the yard and New York State Police state troopers opened fire nonstop for two minutes into the smoke. Among the weapons used by the troopers were shotguns, which led to the wounding and killing of hostages and inmates who were not resisting. Former prison officers were allowed to participate, a decision later called "inexcusable" by the commission established by Rockefeller to study the riot and the aftermath. By the time the facility was retaken, nine hostages and twenty-eight inmates had been killed.

The final death toll from the riot also included the officer fatally injured at the start of the riot and four inmates killed when "inmate justice" was administered. Nine hostages died from gunfire by state troopers and soldiers. The New York State Special Commission on Attica wrote, "With the exception of Indian massacres in the late 19th century, the State Police assault which ended the four-day prison uprising was the bloodiest one-day encounter between Americans since the Civil War."

After the riot, nothing was done to prevent reprisals by troopers and prison officers. Inmates were made to strip, crawl through the mud, and then some were made to run naked between lines of enraged officers, who beat the inmates. Several days after the riot's end, prison doctors reported evidence of more beatings. The commission established by Rockefeller to study the riot and the aftermath accused state officials of allowing rumors to spread, and of unjustifiable delay in denying the false report that one hostage had been castrated and that others had their throats fatally slashed.

Media reports claimed that inmate hostage-takers slit the throats of many of their hostages, reports that contradicted official medical evidence. Newspaper headlines made statements such as "I Saw Slit Throats," implying that prisoners had cut the hostages' throats when the armed raid occurred. These "reports" were later found to be deliberately fictitious. (!!!)

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Many people attribute the riot to the racial issues inside of the prison at the time. Of 2,225 inmates, 54% of the inmates were African American and 9% Puerto Rican; however, all of the 383 correctional officers were white. From reports on the prison conditions, some corrections officers were openly racist and assaulted the prisoners with their batons, which they dubbed "Nigger Sticks." During this time period "black militancy" was at its peak and several prisons had their black militants transferred to Attica. Additionally, George Jackson, a member of the Black Panther Party, died at the hands of white prison officers only a few days before the riot in the San Quentin State Prison in California, and Winston Moseley, Catherine Genovese's murderer, participated in the riot, adding to the racial tension. The aftermath of the riot called for prison reform, especially in the treatment of minority inmates who were becoming a majority in several state correctional facilities across America.

Additionally, Muslims were allegedly targeted by the officers for torture and punishment. It was believed that a group of Muslims were responsible for the uprising and the harm of the hostages, when in fact the group of Muslims were protecting the hostages from other inmates. The leader of the Muslims even told the other inmates that if any of the inmates tried to hurt the hostages, "to kill them [the inmates] or die protecting the hostages."

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A number of former Muslim inmates testified that they had been singled out for "special" brutal treatment by troopers and corrections officers because they had played an active role in protecting the hostages during the four days before the retaking. Because a number of militant inmates were prepared to do harm to the hostages, Frank "Black" Smith, in conjunction with the Muslim leadership, implemented a plan to secure the safety of the hostages during negotiations.

This view was corroborated by Michael Smith, age 51, a former corrections officer

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He never lost consciousness as he laid on the catwalk until a trooper stood over him pointing a shotgun at his head. He was certain that he was going to be killed. A corrections officer saw what was going on and yelled to the trooper, "he is one of us" and then the trooper focused his attention on Don Noble who was still alive. Michael Smith yelled to the trooper, "he saved my life" and the trooper spared Noble.

Try to imagine how it feels to be locked up in a racist torture hole....if I hadn't looked this up, I would have never known.