Robin Williams, the Academy Award winning comedic genius whose pop culture riffs and impressions dazzled critics and viewers, was found by his personal assistant Monday morning in his Tiburon home,  “slightly suspended in a seated position” from a belt around his neck that was wedged between a closet door and the door frame, Marin County assistant chief deputy coroner Keith Boyd announced today at a news conference. The assistant gained access to his bedroom after becoming concerned when he failed to respond to knocks on the door. He already was cold to the touch and rigor mortis had set in. Respondents also found “acute” cuts on the inside of his left wrist and a pocket knife nearby on which was found “dry red material” but those cuts were not the cause of death, Boyd said, explaining the preliminary results support the initial indication the cause of death was asphyxia due to hanging.

Williams, 63, was being treated for depression. Boyd declined to elaborate, citing patients’ right to privacy .

The 911 call came in at 11:55 AM Monday by a “distraught” person who indicated apparent suicide due to hanging,” Boyd said. Emergency crew was dispatched at noon and Williams was pronounced dead at 12:02 PM. Williams was last seen alive at 10:30 PM Sunday when his wife retired for the evening in a room in the home. It was unknown when Williams retired for the evening in his bedroom . At 10:30 AM she left the house “believing him to still be asleep,” Boyd said.

There were no signs of a struggle or altercation, Boyd said, saying an autopsy had been completed but it was unknown if Williams had any chemical substances at the time of death and toxicology results will not be available for two to six weeks.

Williams had acknowledged drug and alcohol problems in the ’70s and ‘80s, and he announced in recent years that he was again drinking, but went back into rehab, joking about it in January to TV critics as he promoted his now-cancelled CBS comedy series The Crazy Ones. “I went to rehab in wine country…to keep my options open,” he joked.