By Associated Press 7:22pm, August 11, 2014 - Updated 9:32pm, August 12, 2014
Robin Williams has died. (Photo by Frank Micelotta/Invision/AP File)Initial autopsy reports confirm that actor and comedic legend Robin Williams committed suicide by hanging.
The Marin County Sheriff's Office says Williams was pronounced dead at his home in California on Monday. The sheriff's office says a preliminary investigation shows signs of asphyxia.
Williams was found dead with a belt around his neck and superficial cuts to his wrist.
The coroner's office confirms Williams was undergoing treatment for depression.
It's unknown whether he had any chemical substances in his system at the time. Toxicology results could take up to six weeks.
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.
Celebrities reflect on Robin Williams' death
Celebrities from Broadway to Hollywood are nearly unanimously in agreement with Steven Spielberg's belief that Robin Williams was a "comic genius."
There is widespread admiration and shock at Williams' apparent suicide at age 63.
Spielberg says Williams was "a lightning storm of comic genius" sustained by the thunder of laughter.
Funny man Steve Martin praised the Oscar-winner's "great talent" but also said he was a "genuine soul." Chevy Chase, who acknowledged that he too suffers from depression, called Williams "a wonderful/man boy."
Former talk show host and comedian Jay Leno says word of Williams' death made it "a very sad day."
Locals remember Williams
"We've all shared a real cultural loss," said Dr. Dwight De-Werth Pallmeyer, associate professor of communications studies at Widener University.
He says Williams, in all of his roles, had a keen ability to make it feel like you really knew him.
His improvisational skills and "his acting is really probably what's really going to standout as we look back on his career, and his ability to use those same skills in serious acting," said De-Werth Pallmeyer.
He says his role in "Dead Poets Society," filmed on the Middletown campus of St. Andrew's School, was extremely powerful.
"One thing that he really brought to the table was this nuanced vulnerability to his characters. If you look back to that role, his vulnerability that he had with his students that brought him into this life, and that's really what a great teacher or professor, I think brings to the table," said De-Werth Pallmeyer.
This material may not be published, broadcast, rewritten, or redistributed.