 Although these bombings were attributed to error, some historians have suspected that the Allies wanted to send a warning to Switzerland for having cooperated with Germany.The daylight bombing of Schaffhausen on 1 April 1944 by the United States Army Air Forces (USAAF) was the most serious of all incidents.Approximately 50 B-24 Liberators of a larger force misidentified Schaffhausen as their target Ludwigshafen am Rhein near Mannheim (about north of Schaffhausen), and dropped sixty tons of bombs on the town.