Operation Chastise was an attack on German dams carried out on 16–17 May 1943 by Royal Air
Force No. 617 Squadron, subsequently publicised as the "Dam Busters", using a specially developed "bouncing bomb" invented
and developed by Barnes Wallis. The Möhne and Edersee Dams were breached, causing catastrophic flooding of the Ruhr valley
and of villages in the Eder valley; the Sorpe Dam sustained only minor damage. Two hydroelectric power stations were destroyed
and several more were damaged. Factories and mines were also either damaged or destroyed. An estimated 1,600 civilians drowned:
about 600 Germans and 1,000 mainly Soviet forced-labourers. The damage was mitigated by rapid repairs by the Germans, but
production did not completely return to normal until September.