Academy Award-winning actor and comedian Robin Williams has died at 63. The cause of death is thought to be suicide by asphyxiation.

Actor Hugh Laurie arrives at the premiere of Universal Pictures and Illumination Entertainment's 'HOP' at CityWalk on March 27, 2011 in Universal City, California.

Actor Robert De Niro presents the Guy Movie Hall of Fame award onstage during Spike TV's 5th annual 2011 “Guys Choice” Awards at Sony Pictures Studios on June 4, 2011 in Culver City, California. (Photo by Kevin Winter/Getty Images)

Actor Woody Harrelson and actress Sofia Vergara onstage during the 69th annual Golden Globe Award Nominations announcements at The Beverly Hilton hotel on December 15, 2011 in Beverly Hills, California. (Photo by Kevin Winter/Getty Images)

Actor Bruce Willis and wife Emma Heming arrive at the premiere of the HBO documentary 'His Way' at Paramount Studios on March 22, 2011 in Hollywood, California.

English comic actor and director Charlie Chaplin (Sir Charles Spencer Chaplin, 1889–1977) seated on straw bales during the filming of “The Circus” with his leading lady Merna Kennedy (1908–1944). (Photo by Margaret Chute/Getty Images). 1928

Charli XCX arrives for the 30th Annual ARIA Awards 2016 at The Star on November 23, 2016 in Sydney, Australia. (Photo by Brendon Thorne/Getty Images)

Actor George Clooney from the film “Ides Of March” arrives at the Hotel Excelsior during the 68th Venice Film Festival on August 31, 2011 in Venice, Italy. (Photo by Gareth Cattermole/Getty Images)