Malcolm-Jamal Warner, the actor, who has died aged 54, was cast as Theo Huxtable in the sitcom The Cosby Show at the age of 13, and over the course of some 200 episodes became one of US television’s best-known teenagers.

W hen Bill Cosby revolutionized television during the mid-1980s with "The Cosby Show," the fictional Huxtables, the wealthy Black family at the center of the sitcom, were often referred to as "America's family," and riding the wave of that pop culture phenomenon was Malcolm-Jamal Warner.

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