Beloved actor Robin Williams was found dead at his home in California Monday morning after what is believed to have been a suicide attempt. He was 63.

Robin Williams Dead At 63

Williams was unconscious and not breathing at his residence in Tiburon, Calif. When medical personnel arrived, he was pronounced dead at 12:02 p.m.

"An investigation into the cause, manner, and circumstances of the death is currently underway by the Investigations and Coroner Divisions of the Sheriff’s Office," reads a statement from the Marin County Coroner obtained by ABC News. “Preliminary information developed during the investigation indicates Mr. Williams was last seen alive at his residence, where he resides with his wife, at approximately 10:00 pm on August 10, 2014."

"At this time, the Sheriff’s Office Coroner Division suspects the death to be a suicide due to asphyxia, but a comprehensive investigation must be completed before a final determination is made,” the statement went on. "A forensic examination is currently scheduled for August 12, 2014 with subsequent toxicology testing to be conducted."

Williams' Rep, Wife Confirm His Passing

Williams' death was confirmed by his rep Mara Buxbaum. "Robin Williams passed away this morning," Buxbaum said in a statement. "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' surviving wife Susan Schneider also released a statement to address her husband’s tragic passing. "This morning, I lost my husband and my best friend, while the world lost one of its most beloved artists and beautiful human beings,” Schneider told The New York Times. “I am utterly heartbroken. On behalf of Robin's family, we are asking for privacy during our time of profound grief. As he is remembered, it is our hope that the focus will not be on Robin's death but on the countless moments of joy and laughter he gave to millions."

Williams was best known for starring in Good Will Hunting – for which he won an Oscar, Dead Poets Society, Good Morning Vietnam and Mrs. Doubtfire, which he was slated to film a sequel for that would be directed by Christopher Columbus. At the time of his death, Williams had three films in postproduction – Merry Friggin’ Christmas, Night at the Museum: Secret of the Tomb and Absolutely Anything. Williams had also recently returned to TV in The Crazy Ones.

Celebs React To Williams' Death

Friends and contemporaries of Williams have taken to Twitter upon learning of his death to mourn the loss of a great man and actor.

Williams is survived by his wife and three children – Zachary Pym, Zelda Rae and Cody Alan.