MARTINEZ -- A man who told authorities that he wanted to hurt himself died Thursday morning, hours after being booked into County Jail in Martinez, a Contra Costa Sheriff's Office spokesman said.

The 24-year-old, whose identity and hometown weren't released pending notification of his relatives, was booked into the facility about 1 a.m. after police arrested him on an outstanding warrant and suspicion of resisting arrest, Sheriff's Office spokesman Jimmy Lee said. During a routine medical screening, the man made statements about wanting to harm himself and was put into a safety cell and checked regularly by deputies, Lee said.

One of the deputy sheriffs found the man unresponsive at about 7:34 a.m. Medical staff at the jail immediately tried to revive him.

An ambulance took the man to Contra Costa Regional Medical Center in Martinez where he was later pronounced dead, Lee said.

The Sheriff's Office and Contra Costa District Attorney's Office are investigating the death. Lee did not release information on a suspected cause of death, or about how the man may have harmed himself if he was in a safety cell and being checked regularly.

The death came almost one year to the day after a Pleasanton man hung himself in the same jail. A deputy sheriff found Joseph Behiel, 21, around 2:55 p.m. on March 21, 2013 after his arrest on weapons charges in San Ramon.Behiel was rushed to the hospital where he died the next day.

A coroner's inquest confirmed the suicide but did not answer questions about why he was left unsupervised despite authorities' knowledge of his mental-health history.

Contact Rick Hurd at 925-945-4789 and follow him at Twitter.com/3rdERH.