Tom Petty died from an accidental drugs overdose

The Los Angeles County Medical Examiner has revealed that Tom Petty died from an accidental overdose of the drugs he was taking to combat emphysema, knee problems and, most significantly, a fractured hip.
Yesterday's toxicology report described the cause of death as: "Multi-system organ failure due to resuscitated cardiopulmonary arrest due to mixed drug toxicity."
The substances found in his system included fentanyl, oxycodone, temazepam, alprazolam, citalopram, acetylfentanyl, and despropionyl fentanyl.
In 2016, fentanyl was a factor in over 64,000 deaths in the United States - a year on year increase of 22%.
The full Medical Examiner's statement reads as follows:

Coroner Case Number 2017-07259 – PETTY, Thomas

The Los Angeles County Department of Medical Examiner-Coroner conducted an examination on the body of Thomas Earl Petty, age 66, on October 3rd, 2017.

The findings of the examination have established the cause of death to be as follows:

Cause of death: Multisystem organ failure due to resuscitated cardiopulmonary arrest due to mixed drug toxicity (fentanyl, oxycodone, temazepam, alprazolam, citalopram, acetylfentanyl, and despropionyl fentanyl)

Other conditions: Coronary artery atherosclerosis, emphysema

How injury occurred: Mixed drug intoxication

The manner of death has been determined to be: Accident

Having been informed beforehand of the findings, Tom Petty's wife, Dana, and daughter, Adria, released a statement explaining why he'd been in so much physical pain and welcoming the renewed discussion about the opioid crisis, which it's likely to trigger.
You can read what they had to say in full here: