Secrets of the Dead on PBS

“Bombing Nazi Dams” chronicles the May 1943 British raid on six Ruhr Valley dams in an effort to deny water to German industry. The weapon: a “bouncing bomb” designed to “skip” across the water and strike the dams from the sides. It was, says narrator Liev Schreiber, “the most ingenious weapon of World War II.” The son and assistant of designer Barnes Wallis describe the design process, and surviving crewmen (almost 40 percent died) recall their ordeal.