Hiroshima and Nagasaki are two cities in Japan that were destroyed by atomic bombs during World War II (1939–1945). The bombs were dropped by the United States in an effort to end the war. Hiroshima was bombed on August 6, 1945; Nagasaki was bombed three days later. The bombs devastated both cities and killed more than one hundred thousand people. Just six days after the cities were bombed, Japan surrendered and World War II came to an end.
The Atomic Bomb
World War II began in 1939, but the United States did not join the fighting at first. On December 7, 1941, the Japanese attacked a US naval base at Pearl Harbor in Hawaii. The attack brought the United States into the war and started a battle for control of the Pacific. By 1945, the United States had defeated the Japanese in several major battles and was advancing toward Japan. The battles were very deadly and thousands of US soldiers were killed. US military officials worried that many more soldiers would die if the United States invaded Japan.
In 1942, the United States began working to build a very powerful weapon called an atomic bomb. The bomb used energy stored in the center, or the nucleus, of an atom. Scientists discovered that large amounts of energy would be produced if the centers of certain types of atoms were split apart. By July 1945, scientists had found a way to use this energy to make an atomic bomb. The president of the United States decided to use the atomic bomb against Japan. He hoped that the bomb would force the Japanese to surrender. That way, the United States would not have to invade Japan.
The target chosen for the first atomic bomb was the city of Hiroshima. Hiroshima was a large city with a population of about 255,000 in 1945. The city was located in southwestern Japan and very important to the Japanese shipping industry. It was also home to many Japanese military bases and more than 40,000 soldiers. The United States chose Hiroshima because it was a key city in the defense of southern Japan.
On the morning of August 6, 1945, a US plane named the Enola Gay dropped an atomic bomb on Hiroshima. The bomb was nicknamed “Little Boy” because of its long, thin shape. The bomb exploded over the center of Hiroshima with a force equal to about 15,000 tons of TNT. It created a large fireball and a huge cloud shaped like a mushroom.
The bomb instantly destroyed about five square miles of the city. Only a few very strong buildings even remained standing. These buildings were built to survive earthquakes, which are very common in Japan. Almost every person close to the center of the blast was killed.
Most people died from burns caused by the fireball. The blast was so powerful that about 30 percent of people more than a mile away were also killed. Experts are still unsure about the number of people who died in Hiroshima. They estimate that between 60,000 and 80,000 people died instantly from the explosion. Many more died later from burns or the effects of radiation. The total death toll in Hiroshima is believed to have been between 90,000 and 166,000 people.
The United States warned Japan that it would drop more atomic bombs, but the Japanese still refused to surrender. US leaders decided to drop a second atomic bomb on August 9, 1945. The original target for the bomb was the city of Kokura. However, when the US bomber plane Bockscar passed over Kokura, the city was covered by clouds. The pilots then chose a second target named Nagasaki.
Nagasaki was a large port city in southern Japan. It had a population of about 240,000 in 1945. At the time of the bombing, about 9,000 soldiers were stationed in the city. Nagasaki was also home to several factories that made weapons and torpedoes.
The bomb dropped on Nagasaki was nicknamed “Fat Man” because of its short, round shape. It exploded with a force of 21,000 tons of TNT. Parts of Nagasaki were also covered by clouds, so the bomb was not dropped on the center of the city. This kept the death toll lower than in Hiroshima. Still, most of the city’s buildings were made of wood and almost all of them near the blast were destroyed. About 40,000 people were believed to have been killed in the explosion itself. Another 40,000 to 50,000 died in the weeks and months after the bombing.
A few days after the Nagasaki bombing, Japan’s emperor decided to surrender. Some military officials wanted to keep fighting, but the emperor decided that the nation had suffered enough destruction. He spoke to the Japanese people on August 15, 1945, and called for an end to the war. Japan officially surrendered on September 2, 1945, bringing an end to World War II.