As Enola Gay winged its way at high altitude toward an unsuspecting city in Japan, Parsons worked in the now-frigid bomb bay with the two uranium masses inserted in the weapon, separated by a hollow tube less than five feet long. Amid bucking turbulence in the extremely cramped space, with his fingers close to frost-bitten, Deke carried out the tasks he had rehearsed hundreds of times in the 100-degree heat on the ground. Sometimes lying under the giant bomb, sometimes straddling it, he tested barometric switches, wired complex circuitry, removed various pins, and gradually transformed the tungsten cylinder into the most deadly weapon yet devised by man.
Parsons was arming the atomic bomb in flight because of the very real possibility that an electrical discharge or a sudden jolt could cause a premature detonation. Better to lose 12 men and a single B-29 than the entire island of Tinian.
With less than five minutes to target, Captain Parsons completed his work. The rest was up to "Little Boy." At 0915, the bomb dropped from the belly of the silver aircraft and plummeted toward Hiroshima. At less than a thousand feet above ground, a great cataclysmic burst of fission changed the world forever.
Deke only lived to the age of 52, dying from a heart attack in 1953. While other naval officers had brought about the great victory at sea in the Pacific theater using guns, periscopes, and tailhooks, Captain William Sterling Parsons had done his part with a slide rule. Yet, in one of those great historical ironies, while thousands would die as a result of Parsons' handiwork, countless thousands of others would live, because "Little Boy," and a second bomb called "Fat Man," would convince the Japanese to surrender, ending the war without a bloody invasion.
In 1977-78, then-Lieutenant Cutler served as operations officer in the USS Parsons (DD-949), a guided-missile destroyer launched in 1958 and named for Deke.