The Marin County, CA Sheriff's Office says actor and comedian Robin Williams was found dead in his home Monday.

Authorities say a 911 call made shortly before Noon Pacific time said Williams had been found unconscious and not breathing inside the home in Tiburon. Emergency personnel arrived shortly after and pronounced Williams dead at the scene.

Williams was last seen alive at the home Sunday night around 10 p.m.

The Sheriff's Office Coroner Division suspects Williams' death to be "suicide due to asphyxia" at this time. A full investigation will determine the cause of death.

A forensic examination is scheduled for Tuesday, with a toxicology test to follow.

Williams was 63 years old.