Einstein had a long history of heart disease, which eventually limited his mobility and stamina. After his radio show was canceled, his appearances were largely confined to Friars' Club roasts. He suffered a fatal heart attack in 1958, at the age of 54, during a roast in honor of Lucille Ball and Desi Arnaz. After Einstein delivered his monologue, emcee Art Linkletter remarked, "Every time he finishes, I ask myself, why isn't he on the air in a prime time?" Einstein turned to Milton Berle, who was seated next to him on the dais, and said, "Yeah, how come?"—then slumped into his lap. Berle's shout of "Is there a doctor in the house?" was initially thought to be a humorous ad lib, but the gravity of the situation quickly became clear.