FILE PHOTO OF ACTOR ROBERT STACK AT DINNER IN LOS ANGELES, 2003-05-12 (photo)

Actor Robert Stack is shown at a dinner for Johnny Grant, honorary mayor of Hollywood, in this file photo from May 12, 2003, in Hollywood. Stack, famed for his television role as crime fighter Eliot Ness in "The Untouchables" and as the host on "Unsolved Mysteries," has died of a heart attack at age 84, his agent said on Thursday. Although ill, Stack had continued to work recently, and his distinct, deep voice will soon be heard as the narrator in the upcoming Broadway revival of "Little Shop of Horrors," which he recorded for the show two or three weeks ago, said Merritt Blake, his agent for the past 25 years. Those recordings were the last work Stack did before his death. REUTERS/Fred Prouser/File FSP/GN