MILPITAS >> Authorities are investigating the death of a 57-year-old male inmate at the Elmwood Correctional Facility in Milpitas.

Deputies found the man unresponsive in his cell at 11:12 a.m. Wednesday, the Santa Clara County Sheriff’s Office said in a statement. He received CPR at the jail and was taken to a hospital, where he was pronounced dead at 5:35 p.m. the same day.

The coroner’s office will release the man’s identity once it is confirmed and his next of kin is notified.

The sheriff’s office said it is following standard protocol for an in-custody death and conducting a joint investigation with the coroner’s and district attorney’s offices.

There were no immediate signs of foul play or suspicious circumstances leading to the man’s death, the sheriff’s office said, adding that he was housed alone at the time.

The man was booked into jail Sunday on drug possession charges stemming from a Los Gatos-Monte Sereno Police Department investigation, the sheriff’s office said.