Sylvester Stallone Opens Up About the 'Devastating' Loss Of Son Sage At 36 In New Netflix Documentary 'Sly'

Sylvester Stallone shares rare insights on his son Sage's untimely death.

In the documentary "Sly," Sylvester Stallone reflects on both his triumphs and regrets, delving into a sensitive topic seldom discussed: the passing of his son Sage Stallone in 2012.

The 77-year-old actor, who has infrequently spoken about Sage's death, reveals that his son succumbed to coronary artery disease atherosclerosis, leading to a fatal heart attack at the age of 36.

A poignant moment in the Netflix documentary, directed by Thom Zimny, features footage of Sage at the age of 14, portraying Robert, the son of Rocky Balboa, alongside his father in the film "Rocky V."

The narrative of the 1990 film revolves around Rocky's challenging relationship with his son, who perceives that Rocky dedicates more time to training with boxer Tommy (Tommy Morrison) than to his own family, including his wife Adrian (Talia Shire).

In the documentary, Stallone reveals that, regrettably, his personal family dynamics played a role in shaping the narrative of "Rocky V," mirroring the way his real-life experiences have influenced other iconic characters like Rocky and Rambo.

Stallone further explains, "I try to take something that actually is what I wish I had done in real life, but I wasn't able to do that in reality. And so quite often I would do it theatrically, magically. … A lot of that is true. Unfortunately, you put things before your family. And the repercussions are quite radical and devastating."

Sage, whom Stallone had with his ex-wife, actress Sasha Czack, was discovered lifeless in his Los Angeles residence on July 13, 2012.

A spokesperson for the actor conveyed the profound grief, stating, "Sylvester Stallone is devastated and grief-stricken over the sudden loss of his son. 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."

In 1996, Sage revealed in an interview that when his character Robert confronts Rocky in the film, expressing frustration about his father not being there for him, it wasn't purely an act -- it resonated with real emotions.

"When I was screaming: 'You never spent time with me! You never spent time with my mother!' that was true. I was looking into my father's face and really saying that," Sage told People at the time.

He went on to explain that the dynamics in real life with Stallone underwent a transformation after art imitated life during the filming of "Rocky V."

"I got a lot of things out. We broke into tears a few times," Sage recalled. "After the film, everything changed. We'd do anything for each other."

Following the display of scenes featuring Sage in "Rocky V," Sly proceeds to present footage from the film's red carpet premiere in 1990.

While standing alongside his son and conversing with reporters, Stallone reflects, "There's a line in the movie, 'I'm so glad he's born because now I can live through your eyes.'"

He continued, "That, I think, is what fathers look to their children for. It's an extension of, a slice of immortality. As long as he's alive, your memory will always be alive, that you did something right. I mean, you hope for that."

In August 2012, Stallone shared with "Good Morning America" that coping with the loss of his son was "very tough."

He admitted, "Time, hopefully, will heal, and you try to get through it, but it's just something," adding. "It's a reality of life. I think it's important to get back and start reliving your life. Otherwise, you can go into a spiral.'

The "Tulsa King" star and Czack also share another son, Seargeoh, 44. He is also a father to daughters Sophia, 27, Sistine, 25, and Scarlet, 21, all of whom he shares with Jennifer Flavin, his wife since 1997.

"Sly" is currently available for streaming on Netflix.