Altogether, 43 men died in the uprising, in which more than 1,200 inmates seized control of the maximum-security prison near Batavia.
The Attica story began on Sept. 9, 1971, when inmates took several guards as hostages and seized control of parts of the prison.
But the number of hostages soon rose to 94 as inmates seized the Atlanta prison hospital and 24 staff members who had barricaded themselves inside it.
As the guards changed shifts at midday on Sunday, the officials said, the inmates broke into an armory and seized 200 rifles.
The inmates had originally seized control of one yard to protest poor living conditions inside the prison, taking 49 guards as hostages.
This causes an uprising and the inmates quickly seize the control of the prison.
Or maybe in the chaos, the inmates seized control and freed themselves.
Four guards were killed when about 10 inmates seized control of the prison on Thursday.
The inmates, who say they are protesting beatings, inadequate medical care and forced transfers to remote places, have seized control of three large prisons.
But sound policy forbids taking firearms into the cell blocks lest inmates seize the weapons.