SAN DIEGO – A 64-year-old man died in his San Diego County jail cell early Wednesday, the 10th such in-custody fatality in a local jail this year.

The man was discovered unresponsive by deputies shortly after midnight as they were doing security patrols on the seventh floor of San Diego Central Jail, sheriff’s Lt. Kevin Ralph said in a news release. Deputies and medical staffers performed life-saving measures including CPR, but he was pronounced dead just before 1 a.m.

Ralph said the inmate was alone in his cell when he was found.

An autopsy by the San Diego County Medical Examiner’s Office found the man died of natural causes, officials announced Thursday.

“Out of respect for his family, we are still unable to release the man’s name until his next of kin has been located and notified of his passing,” the sheriff’s office said in a statement.

The man is the second person to die in a county jail this month. The other in May was 31-year-old Leonel Villasenor, who deputies say was found May 5 slumped over a partition wall next to a toilet while alone in a second-floor holding cell.

Jail deaths keep coming for the agency, which has been under fire this year following the release of a blistering state audit in February. In it, the state auditor noted 185 deaths were tallied in county jails between 2006 and 2020, the most in the state over that period.

It has prompted calls for justice and other reforms in local jails by activists and surviving family members, and likely will play some role in this year’s election to elect the county’s next sheriff.

“There’s a crisis that needs a solution — a solution that will save lives so that other people will not lose loved ones in the custody of law enforcement,” Yusef Miller with the Racial Justice Coalition of San Diego said this month.

No further information was made available on the most recent jail death. It is being investigated by the sheriff’s Homicide Unit. The Citizens Law Enforcement Review Board also has been notified.