When was fatman and little boy dropped

As the plutonium was produced in the nuclear reactors at Hanford, Washington, it was discovered that the plutonium was not as pure as the initial samples from Lawrence's Radiation Laboratory. The plutonium contained amounts of plutonium , an isotope with a rapid spontaneous fission rate. This necessitated that a different type of bomb be designed. As had happened at Hiroshima, the "all-clear" from an early morning air raid alert had long been given by the time the B 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 , 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. 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. 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, feet from ground zero. Of the 52, homes in Nagasaki, 14, were destroyed and 5, 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.

The sealant has been applied. Note the signatures on the tail assembly and the "bomb" on the worker's shirt. Fat Man is lowered on to a transport dolly for the trip to the airfield. Note the signatures on the tail assembly. Signatures on Fat Man's tail assembly. You can see the small signature of "W.

Preliminary pit alignment. Fat Man is manually pushed to the bomb pit. Fat Man's alignment with the bomb pit is checked. The towing cable is disconnected. Note the MPs keeping guard. Fat Man is raised on a hydraulic lift. Once alignment is complete, Fat Man is lowered into the pit.

Fat Man is lowered into the pit. Browse our collection of oral histories with workers, families, service members, and more about their experiences in the Manhattan Project. Sense of Place.