Johnny Johnston, 80, radio host, actor and singer whose recording of "Laura" sold more than 1 million copies. Born in Missouri in 1915, Johnston first gained fame as a junior pocket billiards champion at the age of 16. A big-band singer in the 1930s, he appeared with Art Kassel and His Castles and sang on "The Breakfast Club." During the 1940s, when he recorded "Laura," Johnston hosted a nightly network program for CBS radio and appeared in several films, including "Star Spangled Rhythm," "Sweater Girl" and "You Can't Ration Love." In 1951, he starred with Shirley Booth on Broadway in "A Tree Grows in Brooklyn." In Coral Gables, Fla., of heart failure on Saturday.