LOS ANGELES (CBS) — An 18-year-old inmate died in a Los Angeles County jail after being punched in the face by a sheriff’s deputy during an altercation, a sheriff’s captain said Friday.

George Rosales was found unresponsive in his one-person jail cell in the Twin Towers Correctional Facility at 12:42 a.m. Thursday, said Capt. Mike Parker of the Sheriff’s Headquarters Bureau.

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Jail medical staff performed CPR on Rosales before he was taken to County-USC Medical Center, Parker said. The teen was pronounced dead at 1:30 a.m. Thursday.

Parker said sheriff’s records show Rosales injured himself twice while exercising in his housing area in September. He was seen by medical professionals on both occasions, and taken to a hospital on one occasion.

During an altercation on Tuesday, Rosales was punched in the face by a deputy, Parker said.

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“He was handcuffed, taken to be seen by a jail medical professional, and cleared to return to jail housing,” Parker said.

Around 12:30 a.m. Thursday, a custody assistant reported seeing Rosales drinking water in his cell, Parker said. About 12 minutes later a jail nurse found him in medical distress.

The cause of death is not known and will be determined by the Los Angeles County Coroner’s Office, Parker said.

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