As a result of the mistaken bombing of Freiburg on 10 May 1940 by the German Luftwaffe, 57 inhabitants of Freiburg were killed.
The three aircraft involved of the chain of Lieutenant Paul Seidel from the 8th Season of Fighter Squadron 51, type He 111 had started with their squadron at 14:27 on Landsberg-Lech Air Base so as to bomb the French city of Dijon, or the alternative target Dole–Jura Airport, as part of the Battle of France. However, due to navigation errors they lost orientation and never arrived there. Although they were not able to determine their exact position, they were convinced of being on the other side of the Rhine and, in spite of the landmarks they saw, the town beneath them was thought to perhaps be Colmar, which is at a distance of only 22 miles. Since, on the other hand, the Freiburg Air Guard in Hilda Tower on the Loretto mountain identified the aircraft as German, it was only after the attack was already over that air raid warning was given. Starting from 15:59 the planes dropped a total of 69 bombs on the city.
The German command tried to cover up the mistake and passed the bombing off as enemy action. The German media accepted that version without any hesitation. UFA Weekly Review, for example, reported in its issue no. 506 on 15 May 1940 at the end of a longer contribution of the "brutal and ruthless air raid on an unfortified German city". The newspaper Freiburger Zeitung described it on 11 May 1940 as a "malicious air raid" by the enemy. In the course of this "sneaky, cowardly air raid against all laws of humanity and international law", the newspaper continued "24 civilians were overtaken by death". At the same time the incident was used to justify further attacks against the enemy. Thus, "any further planned bombing of the German population will be counteracted by five times as many German aircraft attacking an English or French town." In a speech at the enterprise Borsig-Werke on 10 December 1940 Adolf Hitler accused the British Prime Minister Winston Churchill to have started with "terrorist" attacks against the civilian population with the bombing of Freiburg.