*According to Michael Clarke Duncan’s newly-released death certificate, the actor died of respiratory failure.


According to TMZ.com, one of the contributing factors to his death was severe lack of oxygen to his brain. Other underlying causes were an irregular heartbeat and acute myocardial infarction, more commonly known as a heart attack..

Duncan died Sept. 3 at 54, having never fully recovered from a heart attack in July.

On Monday, friends and family attended a special service in Los Angeles for “The Green Mile” star.