Michael K. Williams’ cause of death was determined to be a fatal drug overdose.

According to New York City’s Chief Medical Examiner, the actor’s manner of death was acute intoxication due to a lethal combination of fentanyl, p-fluorofentanyl, heroin and cocaine, per TMZ.

The 54-year-old’s death was ruled an accident.

Williams passed away on Labor Day. He was found dead in his Brooklyn apartment, with authorities suspecting an overdose because of the drug paraphernalia at the scene. His death pushed the NYPD to open a probe as they search for the person who sold Williams the drugs.