Events leading up to the Hiroshima A-Bombing (1945)

July 16
First nuclear test in history conducted by the United States (Alamogordo, New Mexico). USS Indianapolis leaves San Francisco for Tinian Island in the Marianas (via Hawaii). Cargo: Portions of uranium 235 and atomic bomb to be dropped on Hiroshima. Scheduled to arrive on July 26. (Other portions of uranium 235 and bomb parts were transported in separate shipments.)
July 25
Order given to drop atomic bomb. (Order issued from US Army General Staff Office to Strategic Air Command in Guam).
July 26
Potsdam Declaration announced in United States, United Kingdom and China, asking for unconditional surrender of Japanese.
July 28
Japan announces it will ignore the Potsdam Declaration.
August 2
US Army Air Force Corps No. 20 field operation order No. 15 issued (August 6. attack Japan. No. 1 target: Hiroshima City industrial sector).
August 5 (Sunday)
21:20
Yellow alert sounded (signals approach of enemy aircraft).
21:27
Air raid warning sounded.
23:55
Air raid warning cleared.
August 6 (Monday)
00:25
Air raid warning sounded.
00:37
Three reconnaissance planes leave Tinian Island in the Mariana Islands heading for Hiroshima, Kokura and Nagasaki to verify weather conditions over target cities. (Japan time)
01:45
B-29 Bomber Enola Gay, carrying A-bomb, leaves Tinian Island. (Japan time) Enola Gay was accompanied by a plane for dropping equipment for measuring the A-bomb's destructive power and another plane for photographing the event.
02:10
Air raid warning cleared.
02:15
Yellow alert cleared. (from 21:20 previous day)
07:09
Yellow alert sounded (B-29 enters Hiroshima air space to verify weather conditions).
07:31
Yellow alert cleared.
08:15
Before air raid warning could alert citizens, A-bomb is dropped and explodes.
August 9
11:02
Plutonium bomb dropped on Nagasaki.
August 10
Japan protests new type of weapon as violation of international law.
August 15
Japan accepts the Potsdam Declaration (Surrenders unconditionally to the Allied Forces).


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