September 9 - September 13, 1971. Near
Buffalo, New York.
A riot over poor prison conditions turned into a 4 day long standoff between prisoners and state police. During the four day period the prisoners negotiated for their surrender and gained support from anti-government groups around the country. News crews were allowed inside to interview the leaders, all while preparations were being made on both sides for a major battle.
On September 13, 1971, 1500 police and national guardsmen stormed the prison. Forty-two people were killed in the conflict, including 10 hostages.