Nuclear fission the Manhattan Project during World War II (September 1, 1939 – September 2, 1945) carried out most of the early scientific work on fission chain reactions, culminating in the three events involving fission bombs that occurred during the war. The first fission bomb, codenamed "The Gadget", was detonated during the Trinity Test in the desert of New Mexico on July 16, 1945. Two other fission bombs, codenamed "Little Boy" and "Fat Man", were used in combat against the Japanese cities of Hiroshima and Nagasaki in on August 6 and 9, 1945 respectively. Even the first fission bombs were thousands of
Mark 15 nuclear bomb is identical to the W39 Mod 0 design). On 5 February 1958, during a training mission flown by a B-47, a Mk 15 nuclear bomb was lost off the coast of Tybee Island, Georgia near Savannah. Mark 15 nuclear bomb The Mark 15 nuclear bomb, or Mk-15, was a 1950s American thermonuclear bomb, the first relatively lightweight (7,600 lb / 3450 kg) thermonuclear bomb created by the United States. A total of 1,200 Mark 15 bombs were produced from 1955 to 1957. There were three production variants: Mod 1, Mod 2, and Mod 3. The design was in service from