World War II began on 1 September 1939 with Nazi Germany’s invasion of Poland, followed by declarations of war on Germany by France and the United Kingdom. Germany invaded the Soviet Union on 22 June 1941, and after Japan attacked Pearl Harbor on 7 December 1941, the US entered the war. In Europe, the turning point came with the German loss to the Russians at the Battle of Stalingrad, and a second front opened on D Day, 6 June 1944, with the invasion of Normandy. Victory in Europe Day was 8 May 1945. In the Pacific, the turning point was the Battle of Midway from 4 to 7 June 1942, when the US defeated Japan. The United States suffered high casualties on Iwo Jima from 19 February 1945 to 16 March 1945 and on Okinawa from 1 April 1945 to 21 June 1945. To prevent further enormous American casualties, President Harry S Truman authorized the first atomic bomb on Hiroshima on 6 August 1945 and a second on Nagasaki on 9 August 1945. Victory over Japan Day on 15 August 1945 ended World War II. Franklin Delano Roosevelt was president until his death on 12 April 1945. The Allied powers, including Russia, the United Kingdom, the United States, and others, sustained 16 million military dead and 45 million civilian dead, while the Axis powers of Germany, Japan, and Italy had 8 million military dead and 4 million civilian dead. Worldwide, World War II caused 73 million total deaths. In the United States, 16 million served in the US Armed Forces, and the US sustained 405,399 killed, including 78,750 missing in action, 671,278 wounded, and 130,201 American prisoners of war.