ABC 20/20 tonight: The Life and Death of Robin Williams

He was the funniest guy in the room, something that made it all the harder for friends and fans to accept that beneath that reservoir of frenetic energy and seemingly endless good humor resided demons so dark they could push Robin Williams to suicide.

It was no secret that the Oscar-winning actor had suffered for years from periodic bouts of substance abuse and depression — he made reference to it himself in his comedy routines.

Tonight, ABC 20/20 will air a retrospective on Williams, exploring who the man was and how and why he may have taken his life.

ABC's 20/20: The Life and Death of Robin Williams airs at 10 p.m. on Channel 9.

Stick around after the show for Eyewitness News at 11 p.m.

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