Frank Sinatra Jr. dead at 72

Frank Sinatra Jr., the son of iconic performer Frank Sinatra, died Wednesday afternoon.

TMZ broke the news, saying Sinatra was in Daytona Beach for a concert when he died of a heart attack. Sinatra's sister Nancy confirmed the news on her Facebook, adding, "Sleep warm, Frankie."

Sinatra followed in his father's footsteps as a singer and was infamously kidnapped and held for ransom when he was 19. He worked closely with his father as his musical director. Sinatra was 72.