A warning was issued to all California prisons after a violent incident at Ironwood State Prison involving 200 prisoners and resulting in injuries to staff members and a prisoner.
The incident occurred during a contraband investigation when the prisoner headbutted a staff member, leading to a rush of prisoners attacking officers with fists and rocks.
The rest of California's prisons were put on a 'modified programming' protocol restricting prisoner movement, but the protocol has since been lifted except for one section of Ironwood that remains under investigation.