During the night of 17 May 1943, as part of Operation Chastise, the Möhnedam was bombed with bouncing bombs. The dam was breached and the valley was inundated with water from the Möhnesee. In the city of Neheim more than 900 people drowned. By using forced labourers the dam was operational again in October 1943. This memorial commemorates the victims of these bombings (including the RAF personnel which lost their lives). The meorial, by Christoph Winkelmann was unveiled on 17 May 2015 by the Heimatverein Möhnesee in cooperation with the Ruhrverband.