TIBURON, Calif. -

Actor Robin Williams has been found dead at his home, the Marin County Sheriff's Office has confirmed. 

Just before noon Monday, Marin County dispatchers received a 911 call reporting a male adult had been located unconscious and not breathing inside his residence in unincorporated Tiburon.

Emergency personnel arrived on scene at 12 p.m. and pronounced the man deceased. They identified him as actor Robin McLaurin Williams, 63.

Sheriff's Lt. Keith Boyd confirmed the investigation to NewsChannel 5 Monday afternoon. The press release is here.

An investigation into the cause, manner, and circumstances of the death is currently underway by the Investigations and Coroner Divisions of the Sheriff’s Office. Preliminary information developed during the investigation indicates Williams was last seen alive at his home at 10 p.m. Sunday.

At this time, the sheriff's office is investigating it as a possible suicide.