Officials at Centinela State Prison are investigating the death of an inmate Monday morning.

The prison says that at about 10:15 a.m. Monday, inmate William Quintero was attacked by two other incarcerated individuals. Quitero, 47, was admitted to the prison system from Los Angeles County in July of 1999. He was serving life without parole for first-degree murder, kidnapping, first-degree robbery and second-degree robbery. Quintero suffered multiple injuries and was airlifted to a Riverside County hospital where he died several hours later. Two inmates believed responsible for the attack have been moved to segregated housing while investigation continues. The inmates were identified as Jose Perez, 46, serving a life sentence without possibility of parole for murder and Juan Serrano, 34, also serving life without the possibility of parole for murder. Two inmate-manufactured weapons were recovered.