Actor Malcolm-Jamal Warner has died suddenly. He was 54. TMZ reports the Cosby Show star died in a drowning accident, though the outlet provided no further details. PEOPLE confirmed the passing, reporting the actor was “on a family vacation and drowned while swimming.

Mr. Warner, who played the only son of Bill Cosby’s character on the beloved 1980s sitcom, drowned in Costa Rica.

The actor, who died Sunday at 54, was best known for his role as Theo Huxtable, the only son of Cliff and Clair Huxtable, who was based on creator Bill Cosby's son.