PHOENIX (AP) - Maricopa County officials say a 61-year-old inmate in Sheriff Joe Arpaio's tent city has died from cardiac arrest.
Authorities say Arthur Madril died Saturday after he was found unresponsive by detention officers.
Officials say officers immediately performed CPR. Phoenix firefighters arrived and later pronounced the inmate dead.
Madril was in custody on a $4000 child support warrant, and was on work release status, meaning he worked during the week and reported to jail every night and weekend.
Friday night Madril returned to jail as normal.
Authorities believe that the inmate died of natural causes but an investigation has been launched into his death.
The Associated Press contributed to this story.