U.S. Drops Atomic Bomb on Hiroshima

What Happened?

At 8:15 a.m. local time, a U.S. B-29 bomber named Enola Gay dropped a five-ton uranium bomb—code-named Little Boy—over Hiroshima. The explosion flattened four square miles and killed around 80,000 people instantly. In the following days and months, tens of thousands more would die from injuries, burns, and radiation sickness.

The decision to use the bomb was made by President Harry Truman, who had recently assumed office after Franklin Roosevelt’s death. With the war in Europe over but Japan refusing to surrender, U.S. leaders believed that invading Japan could cost hundreds of thousands of American lives. The atomic bomb, they argued, would end the war swiftly.

But the human cost was catastrophic. The bomb vaporized entire families, melted steel, and poisoned soil, water, and air. Survivors—known as hibakusha—endured painful burns, trauma, and decades of radiation-related illnesses. Many faced discrimination and isolation, even in their own country.

Historians continue to debate the true motives behind the bombing. Some argue it was a military necessity; others suggest it was meant as a geopolitical message to the Soviet Union. Either way, the blast did more than end a war—it ignited the Cold War and began an arms race that continues today.

Three days after Hiroshima, the U.S. dropped a second bomb on Nagasaki. Japan surrendered days later, on August 15. The world would never be the same. For the hibakusha, their testimony has become a warning: that peace cannot come through nuclear devastation.

Why It Matters

The bombing of Hiroshima marked the dawn of the nuclear age—a moment that forever altered war, diplomacy, science, and human ethics. It reminds us that technology without accountability can lead to unimaginable suffering. The voices of survivors compel us to remember, reflect, and resist repeating history.