At about 2:45 PM on January 22, 2008, Ledger was found unconscious in his fourth-floor loft apartment, at 421 Broome Street, in the SoHo neighborhood of Manhattan.
Emergency crews arrived soon after but were unable to revive him. He was pronounced dead at 3:36 PM, and his body removed from the apartment, while crowds of onlookers began gathering outside throughout that night.
After two weeks of intense media speculation about possible causes of his death, on 6 February 2008, the Office of the Chief Medical Examiner of New York released its conclusions, based on an initial autopsy of January 23, 2008, and a subsequent complete toxicological analysis. The report concludes, in part, "Mr. Heath Ledger died as the result of acute intoxication by the combined effects of oxycodone, hydrocodone, diazepam, temazepam, alprazolam and doxylamine."It also states definitively: "We have concluded that the manner of death is accident, resulting from the abuse of prescription medications." The medications found in the toxicological analysis are commonly prescribed in the United States for insomnia, anxiety, depression, pain, and/or cold symptoms.The Medical Examiner's Office also announced that it would not be publicly disclosing the official estimated time of death. The official announcement of the cause of Ledger's death heightened concerns about general "abuse of prescription medications." Late in February 2008, a still-ongoing DEA investigation of medical professionals "cleared" two American medics, who practice in Los Angeles and Houston, of "any wrongdoing," determining that "the doctors in question had prescribed Ledger other medications – not the pills that killed him."
This was taken from Wikipedia:
http://en.wikipedia.org/wiki/Heath_Ledger
R.I.P Heath Ledger.