An inmate died early Sunday after being found unresponsive at the Santa Barbara County Main Jail, according to the Sheriff’s Department.

Custody deputies discovered the man in his cell shortly after midnight, and life-saving measures were initiated, including CPR and placement of an automated external defibrillator, sheriff’’s spokeswoman Raquel Zick said.

She said Santa Barbara County firefighters and an American Medical Response ambulance were called out.

“Paramedics continued life-saving measures, and the inmate was transported to an area hospital, where he died hours later,” Zick said.

The man had been booked at the jail on Thursday by sheriff’s deputies on suspicion of driving under the influence resulting in injury and hit and run with injuries, both felonies, and misdemeanor reckless driving, Zick said.

He was being held in lieu of $100,000 bail.

“The inmate was housed in a single observation cell due to medical concerns including alcohol detox, and was being checked by staff at regular intervals,” Zick said.

The man’s name was not released pending notification of relatives.

Sheriff’s detectives were conducting multiple investigations into the incident, including a Coroner’s Bureau investigation, Zick said.