Robin Williams

California's Marin County police department announced during a press conference Tuesday that Robin Williams' preliminary cause of death is due to asphyxia from hanging.

"Preliminary results of the forensic examination revealed supporting physical signs that Mr. Williams' life ended from asphyxia due to hanging," Lt. Keith Boyd Assistant Chief Deputy Coroner said. "The forensic examination conducted ... did not reveal any injuries indicating that Mr. Williams had been in a struggle or a physical altercation prior to him being located deceased."

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On Monday afternoon, Marin County Communications received a 911 call at approximately 11:55 a.m. reporting that a male adult had been found unconscious and not breathing inside his residence in Tiburon, Calif. The sheriff's office and the fire department were dispatched to the scene and Williams was pronounced dead at 12:02 p.m.

According to police, "Mr. Williams' personal assistant became concerned ... when he failed to respond to knocks on his bedroom door. At that time the personal assistant was able to gain access to Mr. Williams' bedroom to find Mr. Williams clothed, in a seated position, unresponsive with a belt around his neck, wedged between the closed closet door and the door frame. His right shoulder area was touching the door with his body perpendicular to the door and slightly suspended."

Boyd added: "The inside of Williams' left wrist had several acute superficial transverse cuts [and] a pocket knife with a closed blade was located in close proximity to Mr. Williams."

During the press conference, Boyd explained that Williams' wife Susan Schneider had gone to sleep in a different room than Williams' the night prior and had left the home around 10:30 a.m. Monday, believing him to still be asleep.

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It has not yet been determined whether Williams, who suffered from depression and drug addiction, had any chemical substances in his system at the time of his death. "Toxicology results will not available for approximately two to six weeks while the testing is being performed," Boyd said. "This is an active investigation into the case manner and circumstances of Mr. Williams' death. The work of the coroners' office is not complete. The final cause and manner of death will not be certified until a conclusion of the investigation which is several weeks away."

If you or someone you know needs help, please call the National Suicide Prevention Lifeline at 1-800-273-Talk (8255).