Atomic bombings of Hiroshima and Nagasaki
By August 1945, the Allies' Manhattan Project had produced two types of atomic bombs, and the 509th Composite Group of the United States Army Air Forces (USAAF) was equipped with the specialized Silverplate version of the Boeing B-29 Superfortress that could deliver them from Tinian in the Mariana Islands. Orders for atomic bombs to be used on four Japanese cities were issued on July 25. On August 6, one of the modified B-29s dropped a uranium gun-type bomb codenamed "Little Boy" on Hiroshima. Three days later, on August 9, a plutonium implosion-type bomb codenamed "Fat Man" was dropped by another B-29 on Nagasaki. The bombs immediately devastated their targets. Over the next two to four months, the acute effects of the atomic bombings killed 90,000–146,000 people in Hiroshima and 39,000–80,000 people in Nagasaki; roughly half of the deaths in each city occurred on the first day. Large numbers of people continued to die from the effects of burns, radiation sickness, and other injuries, compounded by illness and malnutrition, for many months afterward. In both cities, most of the dead were civilians, although Hiroshima had a sizable military garrison.
Jacob Beser
On August 6, 1945, the first atomic bomb to be used in combat was dropped by a B-29 Superfortress bomber, the "Enola Gay", over the Japanese city of Hiroshima, killing 70,000 people, including 20,000 Japanese combatants and 20,000 Korean slave laborers. The thirteen-hour mission to Hiroshima under the command of famous pilot Colonel Paul Tibbets, began at 0245 Tinian time. By the time the "Enola Gay" rendezvoused with its two accompanying B-29 Superfortresses at 0607 over Iwo Jima, the group was three hours from the target area. "Little Boy's" detonation was triggered by radar sensors on the bomb that measured its altitude as it fell. Beser's job was to monitor those sensors and ensure that there was no interference that could have detonated it prematurely. The bomb fell away from the aircraft at 09:15:17 Tinian time. Beser did not watch the bomb detonate but he heard the bomb's radar signals switch on and then cut off at the moment the intense light generated by its detonation filled the plane.