On 21 March 1945, after repeated entreaties from the Danish resistance, the RAF approved a planned raid targeting the Danish headquarters of the Gestapo in Copenhagen. In preparation for the raid, a detailed model of the city was built as well as a further model of the buildings to be targeted themselves which were studied for weeks.
The raid was to be carried out by de Havilland Mosquito fast-bomber aircraft, and thus it was that on the morning of 21 March, these aircraft took of in three waves of six along with two Mosquitoes that were to film the raid. Unfortunately, despite successfully targeting the Gestapo headquarters, several bombers in the second and third waves of attack mistakenly targeted a school within which was 529 people; 482 children, thirty-four catholic nuns, eight civil teachers and five parents or workers.
In all, eighty-six children and thirteen adults, mostly nuns, were killed. Separately, over fifty Gestapo members were killed in the attack on the headquarters, along with dozens of Danish workers and several prisoners of the Gestapo. Memorials now stand to the children killed as well as the Danish resistance members.
The footage is available to view on youtube: 1945 Shellhuset bombes - YouTube
RAF - Attack on Gestapo Headquarters
Bombningen af Den Franske Skole blev redigeret ud af erindringen | Information
Google Earth Hacks - French School bombing in Copenhagen 1945
Operation Carthage - Wikipedia, the free encyclopedia
Despite a detailed write-up of this operation, the RAF website makes no mention at all of the scores of children killed; instead, simply referring to the crashing of a Mosquito as ‘the most unfortunate incident of the raid’. Further, the mission is described by them as 'most successful'.