The Atomic Bombings of Hiroshima and Nagasaki

High aerial black and white photo, Hiroshima, pre-bomb
Surveillance image of Hiroshima prior to August 6, 1945

National Archives

Hiroshima (August 6, 1945)- Times are in Tinian Time Unless Otherwise Noted, One Hour Ahead of Hiroshima

0245- Early morning on Tinian, the B-29 Superfortress Enola Gay and her crew of 12 lift off with the uranium bomb Little Boy aboard. The Enola Gay is accompanied by two observation aircraft, The Great Artiste and Necessary Evil.

0320- Little Boy is armed.

0730- Enola Gay Captain Paul Tibbets announces to the crew: “We are carrying the world’s first atomic bomb”.

0809- Air raid sirens begin in Hiroshima.

0912- Enola Gay bombardier Thomas Ferebee takes control of the aircraft as the bombing run begins.

0914:17- Hiroshima’s Aioi Bridge, the target point, comes into view. A 60-second timer commences.

0915:15 (8:15am in Hiroshima)- Ferebee announces “Bomb away” as Little Boy is released from 31,060 feet.
0916:02 (8:16:02am in Hiroshima)- After falling from the Enola Gay for 43 seconds, Little Boy detonates 1,968 feet above Hiroshima, 550 feet from the Aioi Bridge. Nuclear fission begins in 0.15 microseconds.

0916:03 (8:16:03am in Hiroshima, one second after detonation)- The fireball reaches maximum size, 900 feet in diameter. The mushroom cloud begins to form. As temperatures on the ground reach 7,000 degrees Fahrenheit, buildings melt and fuse together, human and animal tissue is vaporized. The blast wave travels at 984 miles per hour in all directions, demolishing over two-thirds of Hiroshima’s buildings in a massive, expanding firestorm. 80,000 people are instantly killed or grievously wounded. Over 100,000 more will die from the bomb’s effects in the coming months.
Aerial photo of Hiroshima mushroom cloud in distance, tall and narrow explosion
Hiroshima, August 6, 1945

National Archives

1055- The U.S. intercepts a Japanese message: “a violent, large special-type bomb, giving the appearance of magnesium”.
Ground photo of the destruction in Hiroshima, very few structures standing
The aftermath of the atomic bombing of Hiroshima

Library of Congress

1458- The Enola Gay lands at Tinian. The mission has lasted twelve hours.

1500- Tokyo news agencies report an attack on Hiroshima. Very few details are given.
Aerial photo of Hiroshima post-bombing, top down view
Hiroshima, five days after the bombing

National Archives

Nagasaki (August 9, 1945)- Times are in Tinian Time Unless Otherwise Noted, One Hour Ahead of Nagasaki

0347- The B-29 Superfortress Bockscar lifts off from Tinian with the plutonium bomb Fat Man aboard. The target is the Japanese city of Kokura.

0351 and 0353- Support planes The Great Artiste and Big Stink lift off from Tinian. Two weather-spotting aircraft, the Enola Gay and Laggin’ Dragon are already airborne.

0400- Cmdr. Fred Ashworth arms Fat Man.

1044- Bockscar arrives at Kokura. Haze makes it too difficult to locate the drop point.

1132- Major Charles Sweeney, Bockscar’s pilot, makes the decision to turn for the secondary target, Nagasaki, 95 miles south of Kokura.

1158- Upon arrival over Nagasaki, cloud cover allows for only one drop point, several miles from the intended target. Bombardier Kermit Beahan releases Fat Man.
Ground photo of the destruction in Nagasaki, very few structures standing
Nagasaki after the atomic bombing

National Archives

1202 (11:02am in Nagasaki)- Fat Man explodes 1,650 feet above the city. Between 40,000-75,000 people die instantly. The bomb creates a blast radius one mile wide. The geography of Nagasaki prevents destruction on the same scale as Hiroshima, yet nearly half the city is obliterated.

2230- All aircraft return to Tinian.

“Hiroshima and Nagasaki Bombing Timeline”, Atomic Heritage Foundation, accessed August 4, 2020,

Manhattan Project National Historical Park

Last updated: August 4, 2020