During World War II, Allied forces were stymied in their attempts to destroy certain German dams. Not only were the dams located deep within well-defended German territory, but they were difficult targets to hit. In order to deal with the second of these problems, Dr. Barnes Wallis invented the bouncing bomb, which would skip across the surface of the water until it reached its target. They were designed to detonate underwater near the dam wall and to use the force of the water behind the dam to destroy the dam wall. A special bomber squadron - the Dambusters - was formed and specially trained for the mission. On May 16, 1943, the new bombs were dropped on the Möhne and Eder dams in the heavily industrialized Ruhr Valley. The dams broke, and water flooded the surrounding areas, taking a toll on German war production in the area. Unfortunately, since the bombers had to fly very low before releasing the bombs, eight of the nineteen planes involved in the raids were shot down before they could return to base.