1 April 1944 (Schaffhausen). Shortly before 11 o'clock on a Saturday morning, a formation of American B-24 «Liberator» bombers, which had taken off from England to strike the IG Farben chemical works in Ludwigshafen, about 200 kilometres further north, mistook Schaffhausen for a German city: bad weather, a strong tailwind and faulty radar had taken it off course. In about forty seconds some 370 high-explosive and incendiary bombs fell on the city. Many inhabitants, used to air-raid alarms, went out into the street to watch the aircraft instead of going down to the shelters.
A city in flames. 40 people died, about 270 were injured and more than 400 were left homeless; over a thousand workers lost their jobs because the factories were destroyed. The station, houses in the old town and the Natural History Museum on the Herrenacker burned. At the Museum zu Allerheiligen, opened in 1938, an incendiary bomb destroyed the room devoted to the Schaffhausen Renaissance painter Tobias Stimmer: more than 80 paintings were lost. It is the most serious bombing ever suffered by a Swiss city.
Apologies, compensation and solidarity. President Franklin D. Roosevelt presented the apologies of the United States, which by October 1944 paid 4 million dollars in compensation. A few days after the bombing the Neue Zürcher Zeitung launched a collection for the museum that raised about 150,000 francs, and cantons, cities and private individuals from all over Switzerland donated some eighty works. For a long time it was believed to be a deliberate punishment of Schaffhausen industries working for Germany; American and British archives show that it was a mistake. Every 1 April the city's bells ring in memory of the victims.
Neutrality violated from the sky (1940–1945). Swiss airspace was constantly crossed by aircraft of both sides: in 1940 Swiss anti-aircraft guns and fighters clashed with the Luftwaffe, and later about 1,700 American airmen landed in Switzerland and were interned. Allied bombs fell on Swiss territory by mistake some seventy times: on 22 February 1945 nine people died in Stein am Rhein, and on 4 March 1945 Basel and Zurich were hit. In 1949 the United States paid Switzerland a further 62 million francs in settlement of all war damage.