Authorities in the San Francisco Bay area confirmed Tuesday comedian Robin Williams committed suicide by hanging himself.

The 63-year-old comedic legend was found Monday by his personnel assistant who expressed concern when Williams didn't answer the door. The actor's wife, Susan Schneider, had left home assuming her husband was still asleep.

Marin County Sheriff Lt. Keith Boyd confirmed Williams committed suicide by hanging himself with a belt. Superficial cuts were on his wrist and a pocketknife was found nearby.

Williams was known to suffer through bouts of depression and struggled with substance abuse for many years. In July, the comedian had re-entered a 12-step treatment program for addiction.

He sought treatment after a relapse in 2006, ending 20 years of sobriety.