Losing a child is an unimaginable pain, one Sylvester Stallone faced in 2012 when his eldest son, Sage Stallone, died at age 36. Known for his role in Rocky V, Sage was a filmmaker and actor who shared his father’s love for cinema.

Born during Stallone’s first marriage to Sasha Czack, Sage had recently undergone dental surgery, having five teeth removed. Despite warnings from his mother about the risks, he proceeded and was prescribed painkillers. Two weeks later, he died from a heart attack caused by atherosclerosis. Though painkillers were found in his system, toxicology ruled out overdose or suicide. The news devastated Stallone, who described Sage as the “center of our universe.” Despite early rumors, Sage did not struggle with substance abuse and had been preparing for his wedding.

Stallone, who overcame a difficult childhood and personal hardships to become a Hollywood icon, leaned on his family to cope. He remains close to his second son, Seargeoh, who has autism, and his three daughters with wife Jennifer Flavin—Sophia, Sistine, and Scarlet.