At 8:15 AM, the American B-29 bomber Enola Gay released 'Little Boy' over Hiroshima, Japan, detonating with a force equivalent to about 15,000 tons of TNT. The blast leveled roughly 70% of the city's buildings and killed an estimated 70,000 to 80,000 people immediately, with total deaths from injuries and radiation sickness eventually reaching over 140,000 by year's end. It remains the first use of a nuclear weapon in warfare.
Colonel Paul Tibbets named the aircraft after his mother, Enola Gay, before the mission. The bomb, a gun-type fission weapon using uranium-235, had never been tested in its exact assembled form before it was used on a live city — the Trinity test weeks earlier had used a plutonium implosion design instead. Physicists monitoring the mission genuinely did not know with certainty how large the blast would be.
Survivors, known as hibakusha, described a flash brighter than the sun, followed by a shockwave that flattened wooden houses like matchsticks and ignited firestorms across the city. Shadows of victims were seared onto stone steps and walls. Sadako Sasaki, a two-year-old at the time, later developed leukemia from radiation exposure and became a global symbol of the bombing's long human toll after folding paper cranes in her hospital bed before her death a decade later.
Three days later, the United States dropped a second bomb on Nagasaki. Japan surrendered on August 15, ending World War II, but the moral and strategic debate over the bombings — whether they were necessary to end the war or a needless atrocity against civilians — has never fully settled.
Key people: Paul Tibbets, Harry Truman, Sadako Sasaki