Guards fired into a “major riot” at California’s Folsom State Prison Friday. Why some 200 inmates began rioting at about 7:30 p.m. last night is not yet known, though the chaos seems to have started with a dispute on the handball court. Seven prisoners sustained non-life-threatening injuries and were taken to local hospitals. No one was killed, and no guards were injured. "The medium-security prison, which holds about 4,000 prisoners, has now been brought under control and the cause of the riot is being investigated," Luis Patino, prison spokesman, said.