Jerod Harris Singer Tom Petty died of an accidental drug overdose that included opioid painkiller Fentanyl, the medical examiner-coroner for the county of Los Angeles announced on Friday. Petty passed away suddenly last October but the cause of his death had remained unclear until now. The singer suffered from knee and hip problems and had been prescribed the medications for pain. Hall of Fame musician Tom Petty died of an accidental drug overdose that included opioid painkiller Fentanyl, the medical examiner-coroner for the county of Los Angeles announced on Friday. The musician had been prescribed pain medications for knee problems and a fractured hip, and was also taking a sleep aid and an antidepressant. In October, at age 66, Petty suffered cardiac arrest at his home in Malibu, California, and passed away shortly after.