A homicide investigation is underway after a 39-year-old inmate at Santa Rita Jail in Dublin died on Wednesday, authorities said.

Yuri Brand, of El Cerrito, was found unresponsive in his cell about 12:23 p.m. during a routine check by deputies, according to the Alameda County Sheriff's Office. Life-saving measures were performed by deputies and paramedics, but Brand died at the scene.

A homicide complaint has been submitted against Brand's cellmate, Bryson Levy, 33, of Oakland, the sheriff's office said in a news release. Levy is scheduled to be arraigned on Sept. 18 in Alameda County Superior Court.

The cause of death is unknown and will be determined by the Alameda County Coroner's Bureau.

Brand was being held at the jail after being arrested Sept. 8 by Piedmont police for trespassing and violating his post-release community supervision, the sheriff's office said. Levy had been jailed by Oakland police on Tuesday for vandalism and violating conditions of his parole.