Hiroshima

In the early morning hours of August 6, 1945, a B-29 bomber named Enola Gay took off from the island of Tinian and headed north by northwest toward Japan. The bomber’s primary target was the city of Hiroshima, located on the deltas of southwestern Honshu Island facing the Inland Sea. Hiroshima had a civilian population of almost 300,000 and was an important military center, containing about 43,000 soldiers.

The bomber, piloted by the commander of the 509th Composite Group, Colonel Paul Tibbets, flew at low altitude on automatic pilot before climbing to 31,000 feet as it neared the target area. At approximately 8:15 a.m. Hiroshima time the Enola Gay released “Little Boy,” its 9,700-pound uranium bomb, over the city. Tibbets immediately dove away to avoid the anticipated shock wave. Forty-three seconds later, a huge explosion lit the morning sky as Little Boy detonated 1,900 feet above the city, directly over a parade field where soldiers of the Japanese Second Army were doing calisthenics. Though already eleven and a half miles away, the Enola Gay was rocked by the blast. The yield of the explosion was later estimated at 15 kilotons (the equivalent of 15,000 tons of TNT).

On the ground moments before the blast… the city was alive with activity — soldiers doing their morning calisthenics, commuters on foot or on bicycles, groups of women and children working outside to clear firebreaks. Those closest to the explosion died instantly, their bodies turned to black char. Nearby birds burst into flames in mid-air, and dry, combustible materials such as paper instantly ignited as far away as 6,400 feet from ground zero. The white light acted as a giant flashbulb, burning the dark patterns of clothing onto skin and the shadows of bodies onto walls. Survivors outdoors close to the blast generally describe a literally blinding light combined with a sudden and overwhelming wave of heat… Those that were indoors were usually spared the flash burns, but flying glass from broken windows filled most rooms, and all but the very strongest structures collapsed. One boy was blown through the windows of his house and across the street as the house collapsed behind him. Within minutes, 9 out of 10 people half a mile or less from ground zero were dead.

Text sourced from US Department of Energy. Images sourced from US National Archives.