Of course, the war did not spare the fortress. The forces of the German Second Army Corps came there on September 10, 1939. Three days later the fortress had been forced by the troops of the “Łódź” Army commanded by General Wiktor Thommée. For the next two weeks, the fortress was besieged by the German forces, which had numerical superiority. The fortress was attacked, shelled and bombarded from the air. The soldiers defended it until September 29, when Warsaw capitulated and the further fights were pointless.
The granary had been attacked as well. During the bombing, the granary was burned inside by incendiary bombs, but thanks to the thick walls, the construction survived. After the war, at the behest of the communist authorities, the demolition of the granary had been started. After destroying the west wing of the building, demolition was stopped by prof. Jan Zachwatowicz, the chief architect of Warsaw rebuilding.