An inmate at the San Diego Central Jail died at the hospital Friday night after deputies found him unresponsive in his cell, according to sheriff’s officials. The 34-year-old man was arrested Thursday on drug-related charges.

A deputy conducting a security check around 7:20 p.m. Friday at the downtown jail discovered a man who was unresponsive inside his cell, according to detectives from the San Diego County Sheriff’s Office. The inmate was housed alone. The deputy immediately requested assistance from jail medical staff, called 911 and began life-saving measures, officials said.

“Paramedics and personnel from the San Diego Fire Department continued resuscitation efforts upon arrival,” SDSO Homicide Lt. Juan Marquez said. “The individual was transported to a local hospital, where he was pronounced deceased at approximately 8:05 p.m.”

The man was arrested by the San Diego Police Department and booked into sheriff’s custody on Thursday. He was facing several possible drug-related charges, according to authorities.

The identity of the man was being withheld pending family notification.

“The San Diego County Sheriff’s Office extends its sympathies to the decedent’s family and all those affected by his passing,” Marquez said. “A Sheriff’s Family Liaison Officer has been assigned to support the family during this difficult time.”

The Citizens’ Law Enforcement Review Board was notified of the incident.

In accordance with protocol for in-custody deaths, the sheriff’s Homicide Unit responded and is conducting an investigation. The cause and manner of death will be determined by the San Diego County Medical Examiner’s Office, officials said.