In 2012 Sylvester Stallone’s eldest son, Sage Stallone, was found dead in his Los Angeles home. He was 36 years old. According to the coroner, Sage Stallone died from a heart attack caused by atherosclerosis. He was a heavy smoker, which was thought to have been a contributing factor. Sage Stallone’s mother was Sasha Czack, who was Sylvester Stallone’s first wife.