Michael Jackson Dead at 50

A report in Britain's The Sun newspaper, citing a UCLA Medical Center source, claims that Jackson received an injection of Demerol -- a drug similar to morphine -- shortly before the incident and began breathing very shallow shortly after. A photo of a police 911 computer purportedly from a call related to Jackson says the subject was "not breathing at all."

The major hazards of meperidine, as with other narcotic analgesics, are respiratory depression and, to a lesser degree, circulatory depression; respiratory arrest, shock, and cardiac arrest have occurred.