The star of Good Will Hunting, Good Morning Vietnam and Mrs Doubtfire, who battled depression and an addiction to cocaine and alcohol for decades, was found 'unconscious and not breathing' in his mansion just outside San Francisco at around noon yesterday. Marin County Sheriff's Office believe Williams asphyxiated himself and an autopsy will be carried out later today. It is not known if he left a suicide note. His distraught wife Susan Schneider, together left, revealed her husband had died and said: 'This morning I lost my husband and my best friend, while the world lost one if its most beloved artists and beautiful human beings. I am utterly heartbroken'. The star's 25-year-old daughter Zelda - one of his three children - tweeted a poignant quote, right. Friends and colleagues like Steven Spielberg, Steve Martin, Danny DeVito, Ellen DeGeneres and Ben Stiller all took to social media to express their grief while theatres and comedy clubs all over America carried their own tributes, inset. Last month the star was back in rehab and his publicist said he had been 'battling severe depression of late'. He was last seen in public on his birthday - July21 - when he posted a photograph of him and and his Night at the Museum co-star, Crystal the monkey.