Tom Petty's Cause of Death Has Been Revealed The Los Angeles County medical examiner released the results of the autopsy on Friday. According to the report, Petty died on Oct. 3 from cardiac arrest as a result mixed drug toxicity. The musician was taking multiple different medications for numerous ailments, including emphysema, knee problems and a fractured hip. "Despite this painful injury he insisted on keeping his commitment to his fans and he toured for 53 dates with a fractured hip and, as he did, it worsened to a more serious injury." "On the day he died he was informed his hip had graduated to a full on break and it is our feeling that the pain was simply unbearable and was the cause for his over use of medication."