Sylvester Stallone's son, Sage Stallone, died from a heart attack, and no drugs were found in his system, according to TMZ.
The L.A. County Coroner determined there was evidence Stallone had heart disease. A source connected to the coroner said it was "unusual" for a person Sage's age -- 36 -- to have such advanced coronary problems.
Stallone's body was discovered July 13, but he may have been dead days earlier. Sources close to the investigation have said that there was evidence of prescription drug use at the scene.