<P> `` Fat Man '' was the codename for the atomic bomb that was detonated over the Japanese city of Nagasaki by the United States on 9 August 1945 . It was the second of the only two nuclear weapons ever used in warfare , the first being Little Boy , and its detonation marked the third - ever man - made nuclear explosion in history . It was built by scientists and engineers at Los Alamos Laboratory using plutonium from the Hanford Site and dropped from the Boeing B - 29 Superfortress Bockscar . For the Fat Man mission , Bockscar was piloted by Major Charles W. Sweeney . </P>
<P> `` Fat Man '' was the codename for the atomic bomb that was detonated over the Japanese city of Nagasaki by the United States on 9 August 1945 . It was the second of the only two nuclear weapons ever used in warfare , the first being Little Boy , and its detonation marked the third - ever man - made nuclear explosion in history . It was built by scientists and engineers at Los Alamos Laboratory using plutonium from the Hanford Site and dropped from the Boeing B - 29 Superfortress Bockscar . For the Fat Man mission , Bockscar was piloted by Major Charles W. Sweeney . </P>
what were the names of the atomic bombs
what were the names of the atomic bombs
Fat Man Little Boy
Fat Man Little Boy