When Robin Williams committed suicide in his Marin County home six years ago this month, his death left a hole in the collective heart of the Bay Area where we long claimed the actor and comedian as our own.

Now, a new documentary may hold answers to everyone's why?, with an inside look at William's struggle against losing his mind to Lewy Body Dementia, a rare disease uncovered posthumously during Williams' autopsy.

As Entertainment Weekly reports, Williams wanted "to help people be less afraid"—that was the legacy he wished for, according to his widow, Susan Schneider Williams. Directed by Tylor Norwood (The United States of Detroit), Robin's Wish, slated for on-demand release September 1st, aims to fulfill that legacy by sharing with the world the struggle of his final days.

"Armed with the name of a brain disease I'd never heard of, I set out on a mission to understand it, and that led me down my unchosen path of advocacy," Schneider Williams said in a statement. "With invaluable help from leading medical experts, I saw that what Robin and I had gone through, finally made sense — our experience matched up with the science. And what I discovered along the way was bigger than me, and bigger than Robin. The full story was revealed during the making of this film and it holds the truth that Robin and I had been searching for."

Watch the official trailer below.

Robin's Wish | Official Trailer (HD) | Vertical Entertainmentwww.youtube.com