Atomic bomb dropped on Hiroshima city


August 12, 2022

The atomic bomb was dropped on Hiroshima City at 8:15 a.m. on Monday, August 6, 1945, toward the end of World War II (the Pacific War). , The United States of America, an Allied power, used the atomic bomb "Little Boy" against the city of Hiroshima, Japan, an Axis power. This is the first nuclear attack on a city in human history. Due to this nuclear attack, 90,000 to 166,000 of the population of 350,000 (estimated) in Hiroshima City at that time are said to have died within 2 to 4 months after the bombing. It is said that 560,000 people were exposed to the atomic bomb, including those who entered the city after the atomic bomb was dropped. Just three days later, on August 9, 1945, an atomic bomb was dropped on the city of Nagasaki. When ``Hiroshima'', which refers to Hiroshima Prefecture, Hiroshima City, etc., is written in katakana as ``Hiroshima'', it is often a reference to the atomic bombing of Hiroshima City. The atomic bomb "Little Boy" (hereafter referred to as the "atomic bomb") dropped on the city of Hiroshima by the US military is also described.

Viewpoint from the bombing side

The rest of this section focuses on the actions of the United States and its ally Britain.

International military background leading up to the atomic bombing of Hiroshima

For details and Japan's response, see "Atomic Bomb Drops on Japan." 1939 8/2 - Jewish physicist who fled to the United States (hereinafter referred to as America) due to the persecution of Jews in Nazi GermanyAlbert EinsteinTo President Franklin Roosevelt "A large amount of uranium causes a nuclear fission chain reactionThe phenomenon is a new bomb It's too heavy to fly on a plane, so it's going to be carried by ship and blown up in a port. I would like to create an advisory body of physicists in the United States studying chain reactions." I wrote a letter (Einstein-Szilard's letter) proposing that 9/1 - World War II broke out after Nazi Germany invaded Poland. October 11 - Einstein's letter mentioned above is delivered to Roosevelt. 10/21 - The United States established the Uranium Advisory Committee. April 10, 1940 - Britain holds the 1st Uranium Explosive Military Applications Committee (MAUD Committee) meeting. 1941 7/15 - The MAUD committee approves the final report that the uranium bomb is feasible and dissolves. October 3 - The final report of the MAUD Commission is officially delivered to President Roosevelt. 12/8 - Japan participates in World War II (Pearl Harbor attack). 1942 September 26 - The U.S. Munitions Production Commission ranks the Manhattan Project as the highest wartime priority class. 10/11 - The United States requests Britain to participate in the Manhattan Project. September 1944 -Hyde Park Memorandum (Quebec Agreement) was exchanged between President Roosevelt and British Prime Minister Winston Churchill, and it was decided to use the atomic bomb against Japan. After that, in April 1945, the first target selection committee was held, and the selection of atomic bomb targets began. July 26, 1945 - Announced the Potsdam Declaration as an ultimatum to Japan.

Order to Drop Atomic Bomb

On July 25, 1945, Manhattan Project director Leslie Groves drafted the drop order (although there is no evidence that it was approved by Harry Truman, Roosevelt's late successor). , The atomic bomb was dropped by Spaatz Army Strategic Air Force Commander (General Commander of Strategic Air Corps) from Deputy Army Chief of Staff Handy.


August 2nd, Guam