Atomic Bombing of Hiroshima (1945)
On August 6, 1945, the United States dropped an atomic bomb on the Japanese city of Hiroshima, killing an estimated 70,000–80,000 people instantly and approximately 90,000–166,000 by the end of 1945. It was the first use of nuclear weapons in warfare and remains one of the most debated decisions in modern history.
The Decision to Use the Bomb
By mid-1945, American forces had defeated Germany and were advancing relentlessly toward Japan through island-hopping campaigns in the Pacific. Yet Japan showed no sign of surrendering. The Battle of Okinawa (April–June 1945) had cost 50,000 American casualties and an estimated 100,000–150,000 Japanese lives, and planners projected that an invasion of the Japanese home islands — Operation Downfall — could cost hundreds of thousands of Allied casualties and millions of Japanese lives. The Trinity nuclear test on July 16, 1945 proved the bomb worked. A target committee had identified cities that were militarily significant, large enough to demonstrate the bomb's full destructive power, and had not already been heavily damaged by firebombing — so that the bomb's effects could be accurately assessed. Hiroshima, the headquarters of the Second Army, was selected as the primary target. President Truman, who had not known of the bomb's existence before taking office after Roosevelt's death in April, approved its use.
Did You Know?
The Hiroshima Prefectural Industrial Promotion Hall — today known as the Atomic Bomb Dome (Genbaku Dome) — was almost directly below the bomb's detonation point and yet its distinctive domed steel skeleton survived, while everything around it was flattened. The ruins were preserved as a memorial and are now a UNESCO World Heritage Site, a few hundred meters from the Peace Memorial Park.
8:15 AM, August 6
The B-29 Superfortress Enola Gay, piloted by Colonel Paul Tibbets and named for his mother, took off from Tinian Island in the Mariana Islands before dawn. At 8:15 AM local time, bombardier Major Thomas Ferebee released "Little Boy" — a uranium gun-type bomb — from 31,000 feet over Hiroshima. It detonated 43 seconds later at approximately 1,900 feet above the Shima Surgical Clinic, 550 feet from the intended aiming point. The fireball reached temperatures of several million degrees Celsius. Everything within half a mile was instantly destroyed. Fires spread across the city. Of Hiroshima's 76,000 buildings, 70,000 were damaged or destroyed. Survivors — the hibakusha — described a blinding flash, a wall of heat, and then silence, followed by a scene of apocalyptic destruction.
Aftermath and the Atomic Age
The Soviet Union declared war on Japan on August 8, and a second atomic bomb was dropped on Nagasaki on August 9. Japan announced its surrender on August 15. The bombings of Hiroshima and Nagasaki inaugurated the Atomic Age and have been debated by historians and ethicists ever since. Critics argue that Japan was already defeated and that alternatives — a blockade, invasion without the bomb, or a demonstration test on an uninhabited area — should have been pursued. Defenders argue that the bombs shortened the war and saved more lives, Allied and Japanese, than they cost. Hiroshima rebuilt and became one of Japan's prosperous cities. The annual Peace Memorial Ceremony on August 6, attended by world leaders, calls for the abolition of nuclear weapons. The city's rebuilt Peace Memorial Museum stands as a direct and unflinching account of what nuclear war means for the people who live beneath it.