The attack, known as "Operation Carthage", came on 22 March 1945, in three small waves. In the first wave, all six planes (carrying one bomb each) hit their target, but one of the aircraft crashed near Frederiksberg Girls School. Because of this crash, four of the planes in the two following waves assumed the school was the military target and aimed their bombs at the school, leading to the death of 123 civilians (of which 87 were schoolchildren). However, 18 of the 26 political prisoners in the Shell Building managed to escape while the Gestapo archives were completely destroyed.