MILWAUKEE (AP) — Authorities say a 35-year-old inmate at the Milwaukee County Jail has died.

The Milwaukee County Sheriff's Office says a correctional officer called medical staff about an inmate in distress Friday afternoon. Authorities say the man was conscious and breathing in the mental health unit at the jail.

Medical staff called for an ambulance and then began CPR when the man stopped breathing. Attempts to revive him failed, and he was pronounced dead.

The inmate was brought to the jail on Oct. 17 by the South Milwaukee Police Department. An autopsy was planned.

The Waukesha County Sheriff's Department will investigate the death.