An investigation will be done into the death of actor Robin Williams.
A 911 call was made just before noon on Monday from a home in Tiburon, California. Emergency personnel arrived within minutes but Williams was already dead.
The Marin County Sheriff's Office says it's believed Williams died in a suicide due to asphyxia.
"Robin Williams passed away this morning. He has been battling severe depression of late. This is a tragic and sudden loss. The family respectfully asks for their privacy as they grieve during this very difficult time," Williams' press representative Mara Buxbaum said in a statement.
Williams shot to fame in the late '70s as the alien in TV's "Mork and Mindy." He conquered the big screen in comic films such as "Good Morning, Vietnam" and "Mrs. Doubtfire." But he won his Academy Award in a serious role - as the therapist in "Good Will Hunting."
His performing style was at its purest in his standup act, as he impersonated a Russian immigrant or parodied anyone from John Wayne to Keith Richards.
In July, the actor spent time in Minnesota at the Hazelden addiction treatment center. Williams was open about the challenge of staying sober; he sought treatment in 2006 when he relapsed and started drinking again.
The actor and comedian was 63.