Rouen was heavily damaged during World War II – approximately 45% of the city was destroyed. In June 1940, the area between the Rouen Cathedral and the Seine river burned for 48 hours as the Germans did not allow firemen access to the fire. Other areas were destroyed between March and August 1944, just before and during the Battle of Normandy, which ended on the left bank of the Seine with the destruction of several regiments belonging to the German 7th Army. Rouen's cathedral and several significant monuments were damaged by Allied bombing. During the German occupation, Nazi Germany's "Kriegsmarine" had its headquarters located in a château on what is now the Rouen Business School (École Supérieure de Commerce de Rouen). The city was liberated by the Canadians on 30 August 1944 after the breakout from Normandy.