During World War II the castle was used as the Tokai district army headquarters and the administration office of the Nagoya POW camp. The aerial bombardments of Nagoya by the United States Army Air Forces as part of the air raids on Japan brought the most destruction to the castle in its entire history. In January 1945 (Shōwa 20), the Sarumen Tea House was destroyed in air raids. On May 14, the main keep, small keep, golden "shachi", Honmaru Palace, northeast turret, and other buildings were completely destroyed in air raids. In June of that year, some of the paintings saved from Honmaru Palace were moved for safekeeping to the Haiho Shrine, Toyota-shi. They returned in May 1946 (Shōwa 21).