Actor Robin Williams has died at 63.
The cause of death is thought to be suicide by asphyxiation.

Here's the release from the Marin County Sheriff's Office:

On August 11, 2014, at approximately 11:55 am, Marin County Communications received a 9-1-1 telephone call reporting a male adult had been located unconscious and not breathing inside his residence in unincorporated Tiburon, CA. The Sheriff’s Office, as well as the Tiburon Fire Department and Southern Marin Fire Protection District were dispatched to the incident with emergency personnel arriving on scene at 12:00 pm. The male subject, pronounced deceased at 12:02 pm has been identified as Robin McLaurin Williams, a 63 year old resident of unincorporated Tiburon, CA.

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. 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. Mr. Williams was located this morning shortly before the 9-1-1 call was placed to Marin County Communications. 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. A forensic examination is currently scheduled for August 12, 2014 with subsequent toxicology testing to be conducted.

Williams is known for his roles in "Good Will Hunting," "Mrs. Doubtfire," and "Hook."

This is major already.....damn. he was sooooo funny....