John Belushi was reportedly drowning himself in alcohol and drugs while trying to turn around his career during his last days at the Chateau Marmont in 1982, and the last people to see him alive were Robert De Niro, Robin Williams and a woman named Kathy Smith – who later pleaded guilty to involuntary manslaughter for supplying the comedian with his last fatal doses of cocaine and heroin, according to a report on a new book about the hotel.