The wiki article says:
"On April 8, 1994, Cobain's body was discovered at his Lake Washington home by an electrician who had arrived to install a security system. Apart from a minor amount of blood coming out of Cobain's ear, the electrician reported seeing no visible signs of trauma, and initially believed that Cobain was asleep until he saw the shotgun pointing at his chin. A suicide note was found that said, "I haven't felt the excitement of listening to as well as creating music, along with really writing . . . for too many years now". A high concentration of heroin and traces of Valium were also found in his body. Cobain's body had been lying there for days; the coroner's report estimated Cobain to have died on April 5, 1994."