SAN JOSE — A man died Monday morning at the Main Jail North in downtown San Jose, authorities said, the third inmate to die while in custody since August.

Around 10:30 a.m., a Santa Clara County correctional deputy found the man, who has not been identified, unresponsive in his cell, said Sgt. James Jensen with the Santa Clara County Sheriff’s Office. After the man was found, custody staff began CPR before paramedics arrived and took over.

Jensen said the man was declared dead shortly after 11 a.m.

Little else was released on the death, including where the man was housed in the Main Jail or how long he had been in custody.

The man will not be identified until his family has been notified of his death, Jensen said.

Monday’s in-custody death was the third for the Santa Clara County Sheriff’s Office since late August.

On Aug. 27, 31-year-old Michael Tyree was found brutally beaten, and three correctional officers — Jereh Lubrin, Rafael Rodriguez and Matthew Farris — face murder charges in connection with his death. Bail for all three was set at $1.5 million. Lubrin posted bail on Sept. 18 and Rodriguez on Sept. 22 or 23.

Tyree had been behind bars for violating probation on a minor drug charge for about two weeks before his death. Judge Steven Manley had wanted to send him to a treatment center for problems that included drug dependency, but until a bed was available, a jail cell was deemed safer for him than the streets.

Tyree had been placed on the sixth floor of the jail, which is reserved specifically for inmates in protective custody or who have special needs. According to a coroner’s report, Tyree suffered serious internal injuries consistent with blunt force trauma, which could have been foot, fist or weapon. In essence, Tyree bled to death internally, the report stated

Since his death, sheriff Laurie Smith has subsequently implemented 40-hour mandatory training for new recruits to the corrections academy on how to better cope with mentally ill inmates. She is also seeking funds to expand and modernize the camera system in the Main Jail and the Elmwood jail in Milpitas. There were no cameras on the sixth floor where Tyree was housed.

On Aug. 31, four days after Tyree’s death, another inmate — a woman identified as 50-year-old Noriko Seales — died from natural causes, specifically a “stroke and hypertensive cardiovascular disease,” according to the Santa Clara County Coroner’s Office. Seales, of Menlo Park, was being held on drug-related charges, according to authorities.

Contact Katie Nelson at 408-920-5006 and follow her at Twitter.com/katienelson210.