Atomic Bombs Destroy Hiroshima and Nagasaki Summary

  • Last updated on November 10, 2022

U.S. military planes dropped atomic bombs on two Japanese cities with consequences both human and environmental that were of unprecedented proportions. Japan surrendered on August 14, leading to the end of World War II and signaling the start of an age of nuclear weaponry.

Summary of Event

At 8:15 a.m. on August 6, 1945, the first atomic weapon ever released over a human population exploded in the air above Hiroshima, Japan. The blast energy and destruction were on a scale hitherto unknown and heralded the beginning of the atomic age. Three days later, on August 9, a second atom bomb was released over the city of Nagasaki at about 11:00 a.m. [kw]Atomic Bombs Destroy Hiroshima and Nagasaki (Aug. 6 and 9, 1945) [kw]Bombs Destroy Hiroshima and Nagasaki, Atomic (Aug. 6 and 9, 1945) [kw]Hiroshima and Nagasaki, Atomic Bombs Destroy (Aug. 6 and 9, 1945) [kw]Nagasaki, Atomic Bombs Destroy Hiroshima and (Aug. 6 and 9, 1945) Atomic bomb Nuclear weapons;Hiroshima and Nagasaki World War II (1939-1945)[World War 02];Japanese campaign Hiroshima, Japan Nagasaki, Japan Fat Man (nuclear bomb) Little Boy (nuclear bomb) Japan;aerial bombardment World War II (1939-1945)[World War 02];atomic bomb Atomic bomb Nuclear weapons;Hiroshima and Nagasaki World War II (1939-1945)[World War 02];Japanese campaign Hiroshima, Japan Nagasaki, Japan Fat Man (nuclear bomb) Little Boy (nuclear bomb) Japan;aerial bombardment World War II (1939-1945)[World War 02];atomic bomb [g]Asia;Aug. 6 and 9, 1945: Atomic Bombs Destroy Hiroshima and Nagasaki[01560] [g]Japan;Aug. 6 and 9, 1945: Atomic Bombs Destroy Hiroshima and Nagasaki[01560] [c]World War II;Aug. 6 and 9, 1945: Atomic Bombs Destroy Hiroshima and Nagasaki[01560] [c]Wars, uprisings, and civil unrest;Aug. 6 and 9, 1945: Atomic Bombs Destroy Hiroshima and Nagasaki[01560] Truman, Harry S. [p]Truman, Harry S.;World War II Truman, Harry S. [p]Truman, Harry S.;nuclear technology Stimson, Henry L. Byrnes, James Francis Groves, Leslie Richard Szilard, Leo

That weapon, originally planned for the city of Kokura—a strategically important location that housed a Japanese army base located only 100 miles west of Hiroshima—was delivered to Nagasaki instead. The weather observation aircraft accompanying the bomber directed the attack toward Nagasaki because of heavy clouds over Kokura. Nagasaki might have escaped destruction on that day had it not been for a small break in the clouds that permitted the crew to release the weapon over a munitions plant.

It has been estimated that the total explosive power of the weapon released over Hiroshima by the B-29 bomber Enola Gay Enola Gay (aircraft) was equivalent to 12.5 thousand tons of trinitrotoluene (TNT). Its explosive power was derived from the fission of uranium 235. The bomb delivered to Nagasaki was almost twice as powerful; its energy came from the fission of the element plutonium. Each of the weapons was equivalent in destructive power to the explosives that might have been carried at that time by a fully loaded fleet of several thousand of the world’s largest bomber planes—an unprecedented release of energy.

Many of those who fell victim to the Hiroshima weapon were engaged on that fateful day in the open air, demolishing structures to provide adequate firebreaks in the event that the city was struck by conventional weapons. Some were volunteer students; others had been drafted by the army for a variety of jobs within the city. It has been estimated that there were about 350,000 individuals in Hiroshima on the morning when the Enola Gay dropped its bomb. Released from an initial altitude of six miles, the weapon exploded about one-third of a mile above the ground, at a point judged to cause maximum damage on the ground below. Both the detonation altitude and the point directly beneath it were later determined from the lengths of shadows cast by standing objects; the shadows were seared into the ground by the intense heat of the explosion.

Seen as an isolated historical event, the release of these two weapons over predominantly civilian populations is almost impossible to comprehend. In 1945, however, following the defeat of Germany by the Allies, the Japanese military was in retreat throughout the Pacific theater. Returning to its homeland, where civilian morale, food, and strategic supplies were already at paralyzingly low levels, the Japanese army was determined to fight to the last soldier, even if it led to the destruction of the entire country and its people.

It was during the meetings in Potsdam, Germany, between the leaders of Russia, Great Britain, and the United States, that news of the first successful nuclear detonation at Alamogordo, New Mexico, was conveyed to President Harry S. Truman. That was in July, 1945, just one month before the bombings. There had been, throughout the preceding months, intense discussions among scientists and between government officials concerning the best strategy for concluding the war in the quickest way.

In 1939, the year in which World War II began in Europe, Hungarian-born physicist Leo Szilard met with Albert Einstein, the most prestigious scientific figure in the world. Szilard was persuasive in expressing his concerns that Germany should not be allowed to be the first to create an atomic weapon, and he enlisted Einstein’s assistance to persuade U.S. president Franklin D. Roosevelt to support a vigorous program of nuclear research. This ultimately led to the formation of the Manhattan Project, the U.S. effort to build an atomic weapon for the United States before the Germans or Japanese, who were known to be vigorously engaged in nuclear research, could build their own.


No other event in recorded history can be compared with the impact of the first uncontrolled release of the energy of the atom. In terms of psychological, social, human, and potential environmental consequences, there were no precedents. People began to come to terms with a force that possessed the potential for the destruction of all life on Earth, including the extinction of the human species itself.

There exist many firsthand accounts by individuals who survived the Hiroshima and Nagasaki bombings. One student recalled that she felt as though she had been struck on the back by a hammer, then thrown into boiling oil, then blown away by the force of the ensuing wind. A five-year-old child who had escaped from entrapment under his house attempted to flee the city and later reported seeing naked people with skin so badly damaged it was hanging from their bodies like rags. Others likened the scene to a painting of Hell. It has been estimated that nearly 50 percent of those who happened to be within a three-quarter-mile radius of the burst point died that day; many more would die subsequently as a result of direct wounds or severe radiation Radiation poisoning exposure.

Prior to the dropping of the atomic bombs, the most severe wartime casualties on Japanese soil had occurred earlier that year in Tokyo, when approximately 10 percent of the city’s population of one million had died of firebombing-related injuries. It has been estimated that nearly 200,000 lives ultimately were lost in Hiroshima within five years of the bombing, and about 74,000 in a similar period in Nagasaki.

The Japanese military was unsure of the nature of the deadly weapon that had been released. Many people believed that everyone would die. Others believed that all natural life in Hiroshima—once regarded as among the most beautiful of all Japanese cities—would perish. During that five-year span, evidence of increased incidences of leukemia, Cancer;and nuclear radiation[nuclear radiation] together with dramatic increases in the rates of other cancers, served to confirm suspicions of delayed effects of nuclear radiation on humans. Survivors of Hiroshima showed a death rate from leukemia seven times higher than the nation’s average, and the incidence of human and animal cancers of all types—breast, lung, thyroid—continued to rise in the following years. Long-term genetic effects were also issues of deep concern for future generations of the survivors of Hiroshima and Nagasaki. The immediate combined losses of life in this brief span of time can be compared to the total loss of U.S. military personnel—about 300,000—in World War II.

In addition to the immediate thermal and blast effects created by the enormous fireball, the fires ignited on the ground gave rise to smoke plumes containing soot and radioactive debris; Radioactive contamination these rose into the atmosphere, where they were absorbed by thunderclouds. This produced the“black rain” that fell in the hours following the explosion. With a sticky, oil-like consistency, it quickly poisoned fish in the local river and deposited its lethal radioactivity onto the skin of the survivors. The black rain suggested that in a large-scale nuclear exchange, dense smoke clouds in the atmosphere could hold the potential for dramatic climate changes. Such sooty smoke would absorb the light of the sun, heating the atmosphere and allowing the surface of the earth to cool. This could have disastrous effects on the earth’s ability to produce crops, and it could also dramatically reduce normal summer temperatures. In Hiroshima, survivors shivered in the middle of summer.

By the spring of 1945, on the verge of successfully achieving and testing the bomb, many atomic scientists, including Szilard, had urged that it not be used against Japan. The war in Europe was ending, and there were increasing concerns that a first-use strategy against a country that was so close to defeat would have serious consequences for the United States in the postwar world. Truman, however, received the advice of an interim committee to drop the bomb as soon as possible. His secretary of state, James Francis Byrnes, seconded that opinion, believing that an unprecedented show of U.S. power would serve to control the postwar expansion of the Soviet Union in Eastern Europe. That view was shared by Secretary of War Henry L. Stimson, who believed further that a postwar sharing of atomic secrets with the Soviets would tend to ensure their good behavior in the postwar world.

Another point of view held that a demonstration of the bomb on some neutral territory might in itself induce the Japanese to surrender. Fears that the still-experimental weapon would fail to detonate, along with concerns that the Japanese military might sabotage the weapon, prevailed when the decision was finally made. The added sense that the United States had within its grasp a tool that could end the war quickly, and so avoid any further losses of the lives of its service personnel, made a compelling argument in favor of the bomb’s use.

Within a few years of the surrender of Japan, several more of the world’s technologically advanced nations had their own atom bombs. In 1954, the United States exploded an entirely different type of weapon, a hydrogen bomb, the energy of which was almost a thousand times that of the Hiroshima device. The postwar years saw the birth of numerous efforts to control the spread and proliferation of nuclear arsenals, which rapidly increased during the Cold War. With the end of the Cold War in the 1990’s, however, genuine nuclear disarmament began to take place, reducing fears of nuclear confrontation and war.

Nuclear proliferation continued to be a threat, however, gaining renewed attention with the growth of terrorist movements with potential access to nuclear materials and the capacity to produce smaller “dirty” bombs. The peaceful exploitation of nuclear energy also expanded greatly, producing about 17 percent of global energy sixty years after the use of atomic weapons against Japan. Atomic bomb Nuclear weapons;Hiroshima and Nagasaki World War II (1939-1945)[World War 02];Japanese campaign Hiroshima, Japan Nagasaki, Japan Fat Man (nuclear bomb) Little Boy (nuclear bomb) Japan;aerial bombardment World War II (1939-1945)[World War 02];atomic bomb

Further Reading
  • citation-type="booksimple"

    xlink:type="simple">Bird, Kai, and Lawrence Lifschultz, eds. Hiroshima’s Shadow. Stony Creek, Conn.: Pamphleteer’s Press, 1998. An excellent resource that explores the moral and ethical aspects of the United States’ decision to drop the atomic bomb on Japan. Also discusses the controversies concerning how to remember this part of U.S. and Japanese history, including the ethics of memorializing the destruction in the Enola Gay exhibition at the Smithsonian in 1995.
  • citation-type="booksimple"

    xlink:type="simple">Fogelman, Edwin. Hiroshima: The Decision to Use the A-Bomb. New York: Charles Scribner’s Sons, 1964. A compilation of contemporary works excerpted from the writings of those involved in the events that led to the bombing. The principal scientists, the decision makers in government, and writers in Japan report on their own perspectives.
  • citation-type="booksimple"

    xlink:type="simple">Hersey, John. Hiroshima. New York: Alfred A. Knopf, 2002. This classic work, written in 1946, adds a chapter written nearly forty years after the original and recounts the author’s search for the six original survivors of Hiroshima whose stories were documented in the first edition of the book. Widely read in its original form (except in Japan, where U.S. authorities blocked its publication until 1949), this work is probably the most moving story of individual human responses to the tragedy.
  • citation-type="booksimple"

    xlink:type="simple">Hogan, Michael J., ed. Hiroshima in History and Memory. New York: Cambridge University Press, 1999. A work of memory and remembrance that focuses on how Hiroshima and Nagasaki have remained as poignant symbols in the national consciousness not only of Japan but also of the United States.
  • citation-type="booksimple"

    xlink:type="simple">Ishikawa, Eisei, and David L. Swain, trans. Hiroshima and Nagasaki. New York: Basic Books, 1981. Prepared by a committee of Japanese commissioned by the two cities to report on the physical, medical, and social effects of the bombings. Contains an extensive bibliography as well as photographs, maps, charts, and tables.
  • citation-type="booksimple"

    xlink:type="simple">Kurzman, Dan. Day of the Bomb: Countdown to Hiroshima. New York: McGraw-Hill, 1986. Written by a former journalist and foreign correspondent, this is a highly readable work with citations from personal interviews, unpublished documents, and papers. Contains an extensive bibliography, including periodical and broadcast materials.
  • citation-type="booksimple"

    xlink:type="simple">Lifton, Robert Jay. Death in Life: Survivors of Hiroshima. 1967. New ed. Chapel Hill: University of North Carolina Press, 1991. Perhaps more than any other writer, Lifton has succeeded in conveying the psychological ramifications of the disastrous events. The research that led to the present work was undertaken in Japan by way of many interviews with survivors and their relatives. Includes an updated preface.
  • citation-type="booksimple"

    xlink:type="simple">Selden, Kyoko, and Mark Selden, eds. The Atomic Bomb: Voices from Hiroshima and Nagasaki. Armonk, N.Y.: M. E. Sharpe, 1989. Mark Selden’s opening chapter reviews, and is highly critical of, the U.S. decision to employ the weapons against Japan. The balance of the book contains four short novels, as well as many poems and drawings, some by authors who were children in Hiroshima at the time of the bombing. Essential reading for an understanding of the events and their impact on the people of the two cities.
  • citation-type="booksimple"

    xlink:type="simple">Walker, Samuel J. Prompt and Utter Destruction: Truman and the Use of Atomic Bombs Against Japan. Rev. ed. Chapel Hill: University of North Carolina Press, 2004. An analysis of President Truman’s decision to drop the atomic bombs. Highly recommended for general readers and students of American and Asian history, World War II, and the atomic age.

World War II: Pacific Theater

Doolittle Mission Bombs Tokyo

United States Develops the First Nuclear Weapon

Superfortress Bombing of Japan

Japan Orders Kamikaze Attacks

First Nuclear Bomb Is Detonated

Hiroshima Recounts the Story of Surviving a Nuclear Explosion

China Explodes Its First Nuclear Bomb

Categories: History