MINNEAPOLIS — It is one of the great mysteries in recent American pop culture: the death of Prince almost one year ago and the circumstances that led him to be found crumpled on the floor of an elevator at his sprawling residence Paisley Park outside of Minneapolis.

How did he come into possession of the powerful opioid fentanyl, which killed him in what the coroner ruled was an accidental overdose? How did he so expertly conceal what appears to have been his addiction to pain medicines? And who, if anyone, bears some responsibility for his demise at 57?

To a surprising degree for a high-profile celebrity death, few answers have emerged for those questions. Many friends still seem at a loss to explain how a man who espoused a clean lifestyle, who had adopted a vegetarian diet and avoided marijuana and alcohol, could have hidden his dependency. Investigators continue their efforts but have given no indication they have discovered where Prince obtained the fentanyl.

This much is clear: Prince suffered from chronic hip pain, and that may have set him on a course to find relief. Surely, near the end, some of those closest to him understood that he had a drug problem. Six days before he died, his chartered jet had to make an emergency landing when he overdosed on a trip home from a concert, and plans were underway to have him see an addiction specialist.