An inmate at the Mendocino County Jail appeared to take his own life in his cell Wednesday night, authorities said.

Shane Murphy, 36, of Cleone, was unconscious when jail staff found him on the floor of his cell at about 11:40 p.m. Wednesday, according to the Mendocino County Sheriff’s Office.

Murphy’s two cellmates had attempted to revive him with CPR without success. Correctional staff took over while an ambulance was summoned.

Murphy was declared dead at the jail.

Murphy, who was arrested by Fort Bragg Police on Tuesday, was booked into the jail the following day on suspicion of carrying a concealed weapon and being under the influence.

The Sheriff’s Office and the Mendocino County District Attorney’s Office are conducting an investigation into Murphy’s death.