July 11, 1946, Radio Daily reports that KLZ AM aired a “simulated atom bomb raid on Denver”. Recorded via wire recorder high above the city in a B-29 aircraft, the broadcast was a promotion for a “CAP-AAF flying show at Lowry Field.”

“KLZ Special Events man Mack Switzer with Engineer Al Raper and Production man Clayton Brace, all wearing head sets and throat mikes, described the event.”

Mack Switzer joined KLZ radio in the early 1940s, and left radio in 1950 going into the ad agency business. Before KLZ he also worked at KOA and KFEL.