Ozzy Osbourne's cause of death has been revealed. The Black Sabbath rocker died at age 76 from a heart attack, according to his death certificate obtained by The New York Times and The Sun. The death certificate reportedly listed Osbourne's cause of death as "out of hospital cardiac arrest,

Ozzy Osbourne died of a heart attack and had coronary artery disease in addition to suffering from Parkinson’s disease for years, his death certificate said.