Cause of Heath's death is a matter of speculation, famous American doctor says it couldn't be natural - Mini Journal -- Mini Journal

Because the autopsy report on Heath Ledger was inconclusive about the cause of death, American television celebrity doctor Drew Pinsky directly stated that it was impossible for Heath Ledger to have died a "natural death". "Even if he had pneumonia, it is uncommon for someone so young to suddenly die. Also, the term natural death is very vague and there is usually a pathological cause, such as arrhythmia. An overdose of medication used to treat pneumonia could be the main reason."