Prince’s heirs have sued Walgreens and the Illinois hospital that treated the music superstar after he suffered from an opioid overdose, alleging that a doctor and various pharmacists failed to provide Prince with reasonable care, contributing to his death.

The wrongful-death lawsuit filed in Cook County, Illinois, alleges a doctor and pharmacist at Trinity Medical Center in Moline, Illinois, failed to appropriately treat and investigate Prince’s April 15, 2016, overdose, and that he died “as a direct and proximate cause of one or more … deviations from the standards of care.”

It accuses Walgreen Co. and pharmacists at two of its Minnesota branches of “dispensing prescription medications not valid for a legitimate medical purpose.”

Walgreens and the hospital’s parent company both declined to comment Monday, citing pending litigation.

Prince was 57 when he was found alone and unresponsive in an elevator at his Paisley Park studio compound in suburban Minneapolis on April 21, 2016. An autopsy found he died of an accidental overdose of fentanyl, a synthetic opioid 50 times more powerful than heroin.

Authorities said it was likely Prince didn’t know he was taking the dangerous drug, which was laced in counterfeit pills made to look like a generic version of the painkiller Vicodin. The source of those pills is unknown and no one has been charged in Prince’s death.

A week before he died, Prince passed out on a flight home from an Atlanta concert and the private plane made an emergency stop in Moline. The musician had to be revived with two doses of a drug that reverses effects of an opioid overdose.

Investigation Says Prince Was Isolated, Addicted And In Pain

At Trinity Medical Center, Prince refused medical tests but was asked what drugs he took. Documents show a pill that he had with him, which was marked as Vicodin, was sent to the pharmacy for testing. A hospital pharmacist said it appeared to be Vicodin and returned it to Prince.

Prosecutors said last week that no chemical testing was done on the pill, but evidence suggests it was counterfeit and laced with fentanyl.

The lawsuit alleges the pharmacist and emergency room physician, Dr. Nicole Mancha, failed to timely diagnose and treat the overdose and failed to provide appropriate counseling.

The allegations against Walgreens stem from prescriptions that were dispensed to Prince, but written under the name of his bodyguard, Kirk Johnson. Authorities said Dr. Michael Todd Schulenberg admitted that he prescribed oxycodone to Prince under Johnson’s name to protect Prince’s privacy. Schulenberg disputes that, but paid $30,000 to settle allegations the drug was prescribed illegally.

Attorneys for Prince’s family, George Loucas and John Goetz, said in a statement that they will have more to say when the time is right.

“Prince’s family wishes, through its investigation, to shed additional light on what happened to Prince. At the same time further light on the opiate epidemic will hopefully help the fight to save lives,” the attorneys said. “If Prince’s death helps save lives, then all was not lost.”