ALBAWABA - Ozzy Osbourne cause of death and more. According to a death certificate made by his daughter and obtained by the Sun and the New York Times on Tuesday, Ozzy Osbourne, lead singer of Black Sabbath and a defining figure in British heavy metal, died of cardiac arrest. He also had coronary artery disease and Parkinson's disease. According to reports, Ozzy Osbourne's daughter Aimée Osbourne filed the death certificate ...