One inmate is dead after a riot broke out Monday morning at Wasco State Prison in Kern County.
Some 40 inmates were involved in the 9 a.m. riot in an exercise yard at the prison reception center, where inmates go to await their long-term assignments at other prisons.
Corrections officers fired a round from a Mini-14 rifle to quell the riot, and three inmates with serious injuries were then taken to a nearby hospital.
Prison officials said one of those men was pronounced dead an hour later. His name was being withheld Monday afternoon while prison administrators tried to contact his family.
Investigators had not yet determined a cause for the violent outbreak, but reception centers tend to be more volatile than other prisons, said Lt. Floyd Harl.
Wasco houses about 5,000 inmates. Harl said the cellblocks where the riot occurred are on lockdown.
No corrections staff were injured.