On 16 Jul 1945, while President of the United States Harry Truman was at Potsdam, Germany to meet with his Allied counterparts, long-waited results reached him: The Manhattan Project, the American effort at building the atomic bomb, successfully detonated the first bomb during a test at Los Alamos, New Mexico, United States. Truman, unwilling to risk the huge amount of lives that might be lost on both sides should the Allies invade the Japanese home islands, ordered the usage of the new technology. The scientists presented them with two such weapons, while the military sought uranium to produce a third.
ww2dbaseTarget Selection
ww2dbaseBetween 10 and 11 May 1945, Oppenheimer led a committee which came up with a list of cities most potentially suitable as targets of atomic attacks. The committee eventually arrived at the recommendation of four targets: Kyoto, Hiroshima, Yokohama, and Kokura.
ww2dbaseHiroshima was chosen as the first target due to its military and industrial values. As a military target, Hiroshima was a major army base that housed the headquarters of the Japanese 5th Division and the 2nd Army Headquarters. It was also an important port in southern Japan and a communications center. The mountains surrounding Hiroshima also contributed to Hiroshima being among one of the top choices among the short list of potential targets, for that the mountains might contain the destructive forces of an atomic blast in the target area, increasing the level of destruction.
ww2dbaseUS Secretary of War Henry Stimson voiced successfully against the selection of Kyoto as a target, arguing that the city held cultural importance to the world; he also had a personal attachment to the city as he and his wife traveled to Kyoto on their honeymoon many years prior.
ww2dbasePrior to the bombing, the United States Army conducted many missions over Japanese cities that were composed of very few B-29 bombers. The purpose of such flights were to wear down the alertness of Japanese anti-aircraft defense crew, whether gunners or fighter pilots, so that when the atomic bomb attacks arrived, perhaps some of the Japanese would let their guards down.
ww2dbaseHiroshima6 Aug 1945
ww2dbaseThe B-29 Superfortress bomber Enola Gay of USAAF 393rd Bombardment Squadron, commanded by Colonel Paul Tibbets of the 509 Composite Bombardment Group, XX Air Force, lifted off from North Field of Tinian of the Mariana Islands on 6 Jun 1945 with their cargo code named "Little Boy". The crew was instructed that Hiroshima was to be their primary target; if Hiroshima could not be reached for any reason, including foul weather, Kokura or Nagasaki was to be chosen as alternate targets. They were accompanied by two other B-29 bombers which carried instrumentation and photography equipment. US Navy Captain William Parsons armed the bomb en route, and 30 minutes prior to reaching Hiroshima 2nd Lieutenant Morris Jeppson removed the bomb's safety devices. Enola Gay was accompanied by two other B-29 bombers: Great Artiste, with scientific instruments, was piloted by Major Charles Sweeney; Necessary Evil, with photography equipment, was piloted by Captain George Marquardt.
ww2dbaseAbout 60 minutes before the American bombers reached Hiroshima, they were detected by Japanese radar. Air raid warnings were sounded in several cities, including Hiroshima, but when it was determined that there were only three bombers, thus it was likely to be only a reconnaissance mission, some of the cities lifted the alarm. The Japanese military determined that aviation fuel was so precious that interceptors would not be launched just for three bombers. This might be caused from the regular visits that the US Army had been sending for the very purpose of making the Japanese lower their guards.
