On April 12, 1945, US President Franklin D. Roosevelt dies from a massive cerebral hemorrhage while sitting for an artist painting his portrait. Vice President Harry S. Truman is sworn in as the 33rd President of the United States.
From July 17 to August 2, 1945, US President Truman, Soviet Union leader Joseph Stalin and British Prime Minister Winston Churchill met at Potsdam, Germany to discuss what to do with post-war Germany. Churchill was replaced on July 26 by newly elected Prime Minister Clement Attlee. Although the three Allied leaders agreed to continue fighting a unified war in the Pacific against Japan, they bitterly disagreed on what to do with Germany. One of the results of the Potsdam Conference was the requirement that Japan agree to an unconditional surrender, but Japan refused, leaving Truman with the decisions over the next week that would change the world and end the war in the Pacific.
On August 6, 1945, an atomic bomb nicknamed ‘Little Boy’ was loaded onto a B-29 bomber named the Enola Gay after the pilot’s mother. At 2:45am, Lt. Col. Paul Tibbets takes off from Tinian Island, in the Marianas and heads for Japan. At 8:16 am, Tibbet is over Hiroshima, Japan when the atomic bomb is dropped and explodes 1,900 feet above the city. The initial blast kills 80,000 Japanese and destroys a large portion of the city. At least 30,000 others were injured at the time of the blast and by the end of 1945, at least 60,000 more Japanese died as a result of the radiation and fallout. The estimated power of the Little Boy atomic bomb was the equivalent to 12,500 TONS of TNT.
Even after the devastating effects of the atomic bomb being dropped on Hiroshima, the Japanese War Council continued to reject the notion of an unconditional surrender. Truman felt he had no alternative at this stage but to give the order for the dropping of a second atomic bomb on Japan.
On this day, August 9, 1945, at 1:56am, a specially rigged B-29 named Bock’s Car, after flight commander Frederick Bock, lifted off the airfield on Tinian Island. The B-29 had been stripped of all armor and weapons in order to allow it to take off with the 11,000-pound payload, an atomic bomb named Fat Man. Bock’s Car was piloted by Major Charles Sweeney. Even stripped of its armor and weapons, a number of experts figured there was a 20% chance that Bock’s Car would crash on takeoff which would have exploded the atomic bomb then as there were no safety devices to stop it.
Initially, the second atomic bomb was scheduled to be dropped on August 11, 1945, but bad weather forced the bombing to be moved up to the 9th. The intended target was the Japanese city of Kokura, but when the B-29 arrived over Kokura, it was obscured by ‘heavy ground haze and smoke.’ The crew had been instructed to use visual instead of radar location to drop the bomb as being off target by as much as a mile or two would have greatly diminished its impact. The crew then turned the plane towards Nagasaki, a town known for a lot of industrialization, even though Nagasaki had been bombed a number of times before with conventional bombs.
On this day, August 9, 1945, at 11:02am, the Fat Man atomic bomb exploded 1,650 feet above the city of Nagasaki. The reason for the elevated explosion was to maximize the devastative force of the atomic explosion. It was estimated that around 70,000 people were killed with the Nagasaki bomb.
US military and civilian participants in the building of the atomic bombs informed President Truman that a third bomb could ready as early as August 17-18, 1945. Even though Japan’s War Council was split on the idea of an unconditional surrender, Truman decided that a third bomb would not be used, but liked the idea of having it ready.
On August 15, 1945, Japanese Emperor Hirohito, announced that he had agreed to an unconditional surrender, making Truman’s decision about dropping a third atomic bomb, unnecessary.
Sources for the above includes: Today, August 6, 1845: Atomic Bomb Destroys Hiroshima; Nagasaki: the Last Bomb; Atomic Bomb Dropped on Nagasaki; The Potsdam Conference, 1945; Unedited Footage of the Bombing of Nagasaki (silent)