To bomb German dams, vital to industry
"Operation Chastise" was carried out by the 617 Squadron of the Royal Air Force, which came to be known as The Dambusters, by launching bouncing bombs invented by Sir Barnes Wallis to skip over the surface of the river until they met the dam and exploded. Two of the three dams targetted were breached, leading to serious flooding although not much else; nearly half of the bombers which took part were lost, but Allied morale jumped.