Sylvester Stallone's son, Sage Moonblood Stallone, was found dead on Friday, July 13. He was only 36 years-old. The elder Stallone is reportedly "grief-stricken" by the news as the cause of death remains unknown. 

Coroner's officials claim to be in the initial steps of investigating the death. Los Angeles police set out to investigate at Mulholland Terrace on Friday afternoon, but could not offer any details about their findings.

However, TMZ is reporting that Sage Stallone's death is the result of "overdose of pills," according to anonymous sources. 

"Sylvester Stallone is devastated and grief-stricken over the sudden loss of his son Sage Stallone," a rep for the actor said in a statement to the media. "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." 

Sage's attorney told the New York Post that he was going to get married.

"He was planning on getting married. I am just devastated. He was an extremely wonderful, loving guy. This is a tragedy," the lawyer, George Braunstein told the paper.

Sage played Rocky's son Robert Balboa on the 1990 film "Rocky 5." He is the son of Sasha Czack, Stallone's first wife.

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