The building survived the Polish Defensive War of 1939 and continued to serve its pre-war role during the German occupation of Poland. In the spring of 1943, in front of it, the Szare Szeregi resistance organization conducted one of its most spectacular actions by liberating a number of political prisoners being transferred by the Gestapo from one prison to another. The operation is hence called Operation Arsenal. The building then saw heavy fighting during the ill-fated Warsaw Uprising of 1944 and was one of the Polish redoubts in the area, defending the area of Warsaw's Old Town from the west. Following the capitulation of the uprising, the arsenal was completely destroyed by the Germans, together with the surrounding buildings and Simmons' passage, one of the most luxurious shopping malls in the inter-war city.