By the end of World War II, much of Europe was devastated. Sustained aerial bombardment during the war had badly damaged most major cities, and industrial facilities were especially hard-hit. Millions of refugees were in temporary camps. The region's trade flows had been thoroughly disrupted; millions were in refugee camps living on aid from the United States, which was provided by the United Nations Relief and Rehabilitation Administration and other agencies. Food shortages were severe, especially in the harsh winter of 1946–47. From July 1945 through June 1946, the United States shipped 16.5 million tons of food, primarily wheat, to Europe and Japan. It amounted to one-sixth of the American food supply and provided 35 trillion calories, enough to provide 400 calories a day for one year to 300 million people.