On 18 August 1943, a bombing raid by the Royal Air Force on Peenemünde ("Operation Hydra") seriously damaged the facilities and ended construction of V-2s there. Other air raids had damaged the other two sites in June and August. As a result, the Nazi leadership accelerated plans to move military construction to areas less threatened by Allied bombers. On 22 August 1943, Adolf Hitler ordered SS leader Heinrich Himmler to use concentration camp workers in future A4/V-2 production. One of the sites selected was at the mountain known as Kohnstein, near Nordhausen in Thuringia. Since 1936, the "Wirtschaftliche Forschungsgesellschaft (WIFO)" () had been building a subterranean fuel depot for the Wehrmacht there. By late summer 1943, this was almost finished.