Sylvester Stallone is mourning the sudden loss of his eldest son.
Sage Stallone -- Sylvester's first child with ex-wife Sasha Czack -- died Friday at the age of 36 of an apparent drug overdose, TMZ reports.
Sources tell the site he was discovered in his Los Angeles apartment; 911 responders pronounced him dead at the scene. (At this point in time, no information is available regarding whether or not the overdose was intentional).
"Sylvester Stallone is devastated and grief-stricken" over his son's passing, the star's rep tells Us Weekly in a statement. "His compassion and thoughts are with Sage's mother, Sasha. Sage was a very talented and wonderful young man. His loss will be felt forever."
Indeed, the two men shared a close bond; Stallone followed in his dad's show business footsteps after making his big-screen debut as a teen in 1990s Rocky V, playing Rocky Balboa's son, Robert.
Stallone would go on to make his directorial debut in 2006 with Vic, which was shown at the Palm Springs Film Festival.
Stallone is survived by his mother, father, and his siblings: brother Seargeoh Stallone, and his half-sisters Sistine, Sophia and Scarlet.