“The gadget” was a test version of the plutonium bomb. It was installed on the top of a 30-meter (100-foot) tower in the New Mexico desert at a location 35 miles southeast of Socorro, New Mexico, on the White Sands Proving Ground. The explosion, called “Trinity,” occurred on July 16, 1945. The energy yield was about 20,000 tons of TNT, more than twice what had been expected. The implosion-type bomb was much safer and more effective than the cannon-style “Little Boy” design and has been used for all other nuclear weapons.