Manhattan Project: The Atomic Bombing of Nagasaki, August 9, 1945

THE ATOMIC BOMBING OF NAGASAKI
(Nagasaki, Japan, August 9, 1945)
Events > Dawn of the Atomic Era, 1945

The next break in the weather over Japan was due to appear just three days after the attack on Hiroshima, to be followed by at least five more days of prohibitive weather. The plutonium implosion bomb, nicknamed "Fat Man," was rushed into readiness to take advantage of this window. No further orders were required for the attack. Truman's order of July 25th had authorized the dropping of additional bombs as soon as they were ready. At 3:47 a.m. on August 9, 1945, a B-29 named Bock's Car lifted off from Tinian and headed toward the primary target: Kokura Arsenal, a massive collection of war industries adjacent to the city of Kokura.

From this point on, few things went according to plan. The aircraft commander, Major Charles W. Sweeney, ordered the arming of the bomb only ten minutes after take-off so that the aircraft could be pressurized and climb above the lightning and squalls that menaced the flight all the way to Japan. (A journalist, William L. Laurence of the New York Times, on an escorting aircraft saw some "St. Elmo's fire" glowing on the edges of the aircraft and worried that the static electricity might detonate the bomb.) Sweeney then discovered that due to a minor malfunction he would not be able to access his reserve fuel. The aircraft next had to orbit over Yaku-shima off the south coast of Japan for almost an hour in order to rendezvous with its two escort B-29s, one of which never did arrive. The weather had been reported satisfactory earlier in the day over Kokura Arsenal, but by the time the B-29 finally arrived there, the target was obscured by smoke and haze. Two more passes over the target still produced no sightings of the aiming point. As an aircraft crewman, Jacob Beser, later recalled, Japanese fighters and bursts of antiaircraft fire were by this time starting to make things "a little hairy." Kokura no longer appeared to be an option, and there was only enough fuel on board to return to the secondary airfield on Okinawa, making one hurried pass as they went over their secondary target, the city of Nagasaki. As Beser later put it, "there was no sense dragging the bomb home or dropping it in the ocean."

As it turned out, cloud cover obscured Nagasaki as well. Sweeney reluctantly approved a much less accurate radar approach on the target. At the last moment the bombardier, Captain Kermit K. Beahan, caught a brief glimpse of the city's stadium through the clouds and dropped the bomb. At 11:02 a.m., at an altitude of 1,650 feet, Fat Man (right) exploded over Nagasaki. The yield of the explosion was later estimated at 21 kilotons, 40 percent greater than that of the Hiroshima bomb.

Nagasaki was an industrial center and major port on the western coast of Kyushu. As had happened at Hiroshima, the "all-clear" from an early morning air raid alert had long been given by the time the B-29 had begun its bombing run. A small conventional raid on Nagasaki on August 1st had resulted in a partial evacuation of the city, especially of school children. There were still almost 200,000 people in the city below the bomb when it exploded. The hurriedly-targeted weapon ended up detonating almost exactly between two of the principal targets in the city, the Mitsubishi Steel and Arms Works to the south, and the Mitsubishi-Urakami Torpedo Works (left) to the north. Had the bomb exploded farther south the residential and commercial heart of the city would have suffered much greater damage.

In general, though Fat Man exploded with greater force than Little Boy, the damage at Nagasaki was not as great as it had been at Hiroshima. The hills of Nagasaki, its geographic layout, and the bomb's detonation over an industrial area all helped shield portions of the city from the weapon's blast, heat, and radiation effects. The explosion affected a total area of approximately 43 square miles. About 8.5 of those square miles were water, and 33 more square miles were only partially settled. Many roads and rail lines escaped major damage. In some areas electricity was not knocked out, and fire breaks created over the last several months helped to prevent the spread of fires to the south.

Although the destruction at Nagasaki has generally received less worldwide attention than that at Hiroshima, it was extensive nonetheless. Almost everything up to half a mile from ground zero was completely destroyed, including even the earthquake-hardened concrete structures that had sometimes survived at comparable distances at Hiroshima. According to a Nagasaki Prefectural report "men and animals died almost instantly" within 1 kilometer (0.62 miles) of the point of detonation. Almost all homes within a mile and a half were destroyed, and dry, combustible materials such as paper instantly burst into flames as far away as 10,000 feet from ground zero. Of the 52,000 homes in Nagasaki, 14,000 were destroyed and 5,400 more seriously damaged. Only 12 percent of the homes escaped unscathed. The official Manhattan Engineer District report on the attack termed the damage to the two Mitsubishi plants "spectacular." Despite the absence of a firestorm, numerous secondary fires erupted throughout the city. Fire-fighting efforts were hampered by water line breaks, and six weeks later the city was still suffering from a shortage of water. A U.S. Navy officer who visited the city in mid-September reported that, even over a month after the attack, "a smell of death and corruption pervades the place." As at Hiroshima, the psychological effects of the attack were undoubtedly considerable.

As with the estimates of deaths at Hiroshima, it will never be known for certain how many people died as a result of the atomic attack on Nagasaki. The best estimate is 40,000 people died initially, with 60,000 more injured. By January 1946, the number of deaths probably approached 70,000, with perhaps ultimately twice that number dead total within five years. For those areas of Nagasaki affected by the explosion, the death rate was comparable to that at Hiroshima.

The day after the attack on Nagasaki, the emperor of Japan overruled the military leaders of Japan and forced them to offer to surrender (almost) unconditionally.

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Sources and notes for this page.

Portions of the text for this page were adapted from, and portions were taken directly from the Office of History and Heritage Resources publication: F. G. Gosling, The Manhattan Project: Making the Atomic Bomb (DOE/MA-0001; Washington: History Division, Department of Energy, January 1999), 53-54. Also used was the report on "The Atomic Bombings of Hiroshima and Nagasaki" in the official Manhattan District History, produced by the War Department in 1947 at the direction of Leslie Groves, especially pages 1-19; the "Atomic Bombings" document is available in the University Publications of America (UPA) microfilm collection, Manhattan Project: Official History and Documents (Washington: 1977), reel #1/12; the report itself is a government document. For an account of the mission, see the "Eye Witness Account: Atomic Bomb Mission Over Nagasaki" press release, written by William L. Laurence of the New York Times and released on September 9, 1945; this is also available on reel #1/12 of the UPA Manhattan Project microfilm collection. Summaries of Hiroshima and Nagasaki casualty rates and damage estimates appear in Leslie R. Groves, Now It Can Be Told (New York: Harper & Row, 1962), 319, 329-330, 346, and Vincent C. Jones, Manhattan: The Army and the Atomic Bomb, United States Army in World War II (Washington: Center of Military History, United States Army, 1988), 545-548. For a description of Kokura Arsenal and interesting reflections on its postwar fate, see "Chapter 4: Kokura" of Paul Saffo's essay "The Road from Trinity: Reflections on the Atom Bomb"; this is available on Paul Saffo's web site at http://www.saffo.com/essays/the-road-from-trinity-reflections-on-the-atom-bomb/. The map showing the flight paths for the Hiroshima and Nagasaki missions is reproduced from Gosling, Making the Atomic Bomb, 52. The photographs of Fat Man and of the general devastation at Nagasaki are courtesy the U.S. Army Corps of Engineers (via the National Archives (NARA)). The photograph of the destruction at the Mitsubishi facility north of ground zero is courtesy the Los Alamos National Laboratory; the photograph was taken by Robert Serber and is reprinted in Rachel Fermi and Esther Samra, Picturing the Bomb: Photographs from the Secret World of the Manhattan Project (New York: Harry N. Abrams, Inc., Publishers, 1995), 190. The photograph of the mother and child is courtesy the Department of Energy (via NARA). The photograph of the bodies in the trench is reprinted from Vincent C. Jones, Manhattan: The Army and the Atomic Bomb, United States Army in World War II (Washington: Center of Military History, United States Army, 1988), 548.

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