Atomic Bombing of Hiroshima

Utter destruction of Hiroshima by 6 August 1945 bombing with a single atomic weapon.  Written note is from Colonel Paul W. Tibbets, Jr.
Utter destruction of Hiroshima by 6 August 1945 bombing with a single atomic weapon. Written note is from Colonel Paul W. Tibbets, Jr. Click photo for larger size image.

The first and only use of nuclear weapons in combat was in August 1945 when the United States dropped atomic bombs on two Japanese cities, Hiroshima and Nagasaki. The stunning destruction brought by these individual weapons, delivered by single airplanes, convinced the Japanese government that continuation of the war was futile.

An invasion of the Japanese home islands was thereby avoided, doubtless saving many lives on both sides. The surrender on 14 August 1945 ended more than a decade of Japanese aggression in Asia and the Pacific and three and one-half years of brutal warfare following Pearl Harbor.

This page describes what happened at Hiroshima, the first atomic bombing.

Today in WW II: 20 Oct 1941 In reprisals for losses to Yugoslavian partisians, Germans troops kill thousands of civilians in Kragujevac and Kraljevo [20-21 Oct].  More 
20 Oct 1944 Philippines invaded by Allies at Leyte, joined by Filipino guerillas.
20 Oct 1944 Gen. Douglas MacArthur Returns to Leyte, Philippine Islands.
20 Oct 1944 Belgrade, Yugoslavia liberated by Russian Red Army aided by Yugoslav Partisans.
Visit the World War II Timeline for day-by-day events 1939-1945! See also WW2 Books.

Preparations for Hiroshima, the First Atomic Bombing

On 25 July 1945, the U.S.S. Indianapolis delivered the components of the atomic bomb to the 509th on Tinian. When assembled, the uranium bomb, called "Little Boy" weighed 9,700 lbs, was ten feet long, with a diameter of 28 inches. The photo to the right shows Little Boy in the loading pit, directly under the Enola Gay, ready to be hoisted into its bomb bay. Navy Captain Deak Parsons (Ordnance Chief and Associate Director at Los Alamos , on board Enola Gay as Weapon Officer), assisted by Lt. Morris Jeppson (Weapon Test Officer, electronics specialist), finished the assembly and arming in the bomb bay after takeoff, out of fear that an armed bomb could explode on Tinian or in a crash during take-off.

Hiroshima, 6 August 1945

Hiroshima, a military center and the seventh largest city in Japan at the time, was selected as the first target for the 509th Composite Group bombers. At 2:45 AM on Monday, 6 August 1945, a B-29 Superfortress bomber 'Enola Gay' (named after the mother of pilot Colonel Paul W. Tibbets, Jr.), took off from Tinian, a North Pacific island in the Marianas, only 1,450 miles from Tokyo, carrying the bomb. Major Charles W. Sweeney, commander of the 393rd Bomb Squadron, accompanied the Enola Gay on the mission, piloting the B-29 'The Great Artiste' as an observation aircraft. A second B-29 observation plane was also on the mission, three planes in all.

No one was sure whether the weapon would detonate or what would happen if it did. The bomb was on target at 8:15 AM local time, was released from 31,600 feet, and exploded 50 seconds later 1,900 feet above the Aioi Bridge. The bomb produced a yield of approximately 15,000 tons of TNT, a tonnage roughly seven times all of the bombs dropped on Germany in 1942. The airburst above the city created a 1000 foot wide fireball with temperature at ground zero of 5,000 degrees centigrade and a shock wave travelling close to the speed of sound. A mushroom cloud rose 20,000 feet in the air (photo, left).

Sixty percent of the city was destroyed. In a radius of three miles of ground zero, two-thirds of the 90,000 buildings were demolished (photo, top). There was a prompt loss of life of an estimated 70,000 people, and as many deaths within five years from radiation and other injuries.

Find More Information on the Internet

There are many fine websites that have additional information on this topic, too many to list here and too many to keep up with as they come and go. Use this Google web search form to get an up to date report of what's out there.

For good results, try entering this: atomic hiroshima. Then click the Search button.

Especially recommended: