Nicknamed ‘the gadget’ by the people working on it, the plutonium-based weapon was detonated at the Alamogordo Test Range in New Mexico. The explosion was equivalent to about 20 kilotons of TNT, and the blast-wave was felt by civilians up to 160 miles away. To maintain secrecy, a press release was issued shortly after the successful detonation that claimed a large ammunition storage magazine had exploded.
The development of nuclear weapons by the US Army in the Manhattan Project that began in 1942 at Los Alamos Laboratory in New Mexico started due to concerns that Nazi Germany would develop an atomic bomb. By 1944 scientists had designed an implosion-type device and proposed that a test take place. The location was chosen in September, and an on-site laboratory was set up.
President Truman was keen to test the bomb before the Potsdam Conference began on the 18th July, so the 16th was chosen to give time to try again in case it failed. However when the appointed hour came rain was falling, which would have increased radioactive fallout, and so the detonation time was pushed back from 4am to 5.30am. At 5:29am the “the gadget” was exploded on top of a 100-foot steel tower, known as Point Zero. J. Robert Oppenheimer, the director of the Los Alamos Laboratory, later said that after the explosion he recalled a verse from Hindu scripture: 'Now I am become Death, the destroyer of worlds.'
