A man doing yard work at a Riverside home was found dead in the backyard septic tank on Thursday afternoon.

According to the Riverside Police Department, the 52-year-old man sometimes stayed with relatives who live at the home in the 1600 block of Oxford Street. He was last seen working in the yard at approximately 10 a.m.

A heavy-duty vacuum cleaner had been running for an extended period of time when a family member went to look for the man and found him unconscious in the underground septic-tank enclosure at approximately 3:15 p.m.

Emergency personnel determined the man had died.

Because of the body’s location, it was removed by the Riverside Fire Department Hazardous Materials team.

The coroner will investigate the cause of death.

– posted at 7:31 p.m. by Cathy Maestri