A Southern California serial killer Andrew Urdiales and notorious mass murderer Virendra Govin reportedly committed suicide in their San Quentin Prison cells over the weekend, according to ABC 7.

Both men were reportedly locked in separate cells by themselves and their deaths are not believed related, the station reported.

Urdiales, a 54-year-old former Marine who was sentenced October 5 to death for slaying five Southern California women from 1986 to 1996, was found unresponsive in a cell at the prison’s Adjustment Center late Friday night, the station reported.

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The slayings were reportedly carried out while Urdiales was stationed at Camp Pendleton. Previously, he received the death penalty in Illinois for three murders but his sentence was commuted to life in prison when capital punishment in that state was abolished in 2011, Fox News reported.

Govin, 51, was found dead Sunday night dead in a cell in San Quentin’s North Segregation housing unit. He was sentenced to death in 2004 for “strangling, beating” four members of a family who owned a motel next to his in Studio City and then setting their home on fire.

His brother, Pravin Govin, remains on death row for the same crime.

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[Feature Photo: Andrew Urdiales & Virendra Govin /California Department of Corrections and Rehabilitation]