SAN RAFAEL: Oscar-winning actor and renowned comedian Robin Williams hanged himself in his California home and died by asphyxia, a coroner said on Tuesday based on preliminary findings.

Williams, 63, was found dead by his personal assistant at midday on Monday, suspended from a belt wedged between a door and a door frame in a seated position just of the ground, Marin County's assistant chief deputy coroner, Keith Boyd, told a news conference.

“Mr. Williams' personal assistant became concerned at approximately 11:45 am when he failed to respond to knocks on his bedroom door,” said Boyd.

“His right shoulder area was touching the door with his body perpendicular to the door and slightly suspended. Mr. Williams at that time was cool to the touch with rigor mortis present in his body,” Boyd added.

Officials also found a pocket knife near Williams and cuts with dried blood on his wrist that matched the knife blade.

Williams had been seeking treatment for depression, Boyd said. He would not discuss if had left a suicide note.

Funeral arrangements would be decided by the family, Boyd said. His body has been released by the coroner facility in neighboring Napa County.

Boyd would not say if any drugs or alcohol were involved and that the full toxicology report would take several more weeks, stressing that the investigation was continuing.

Comedians, politicians and several generations of fans collectively mourned the death of Williams, famous for his frenetic and freewheeling comedy.

The news of Williams' death rippled across social media, stunning fans young and old and comedians who had been influenced by Williams since he broke out in the 1970s TV comedy “Mork & Mindy” as a strange and lovable creature from outer space.

Williams had been open about his struggles with alcohol and cocaine and in the past months had entered a rehabilitation center to help him maintain sobriety.

But many questions remained over his final months and what could have led to his apparent suicide.

On the Hollywood Walk of Fame, dozens of fans congregated around Williams' star early on Tuesday, leaving flowers and candles to honor the versatile actor.

Williams' appeal stretched across generations and genres, from family fare as the voice of Disney's blue Genie in “Aladdin” to his portrayal of a fatherly therapist in the 1997 drama “Good Will Hunting,” for which he earned his sole Oscar.

The death of Williams shook Hollywood and colleagues mourned the loss of what many called a big-hearted man and one of the most inventive comedians of his time.

Sarah Michelle Gellar, who played his daughter in the recent CBS television comedy, “The Crazy Ones,” said her life was better for knowing Williams. Their show was canceled in May after one season.

“To my children he was Uncle Robin, to everyone he worked with, he was the best boss anyone had ever known, and to me he was not just an inspiration but he was the father I had always dreamed of having,” Gellar said in a statement.