Malcolm-Jamal Warner, who played Theo Huxtable on "The Cosby Show," has died at 54, with Bill Cosby reflecting on their relationship and Warner's professionalism on set.

Malcolm-Jamal Warner's cause of death has been released by police. The actor, who is best known for his role as Theo Huxtable in the hit TV sitcom "The Cosby Show," died on Sunday off the coast of Costa Rica after a drowning, Costa Rican National Police told ABC News. He was 54.