How do you test an atomic bomb in secret?
Development of the atomic bomb was the most closely guarded secret of World War II, but one aspect of the work was impossible to keep under wraps: a test of the finished device in the New Mexico desert.
When scientists detonated the bomb at 5:29 a.m. local time on July 16, 1945, its effects were noticeable hundreds of miles away. "The blast rattled windows, blew doors open and awoke many sound sleepers," reported the Gallup Independent, some 240 miles from the test site.
"Reports from over the state listed the blast variously as an earthquake, meteor and airplane crash," the Albuquerque Journal reported. "Members of the crew and passengers aboard a Santa Fe railway train near Mountainair thought they saw a bomber explode and burn in the sky.
"So brilliant was the flash from the explosion Miss Georgia Green of Socorro, blind University of New Mexico student, exclaimed, "What's that."
The official answer to the question posed not only by those in New Mexico, but parts of Arizona and Texas as well, came from Col. William O. Eareckson, the commanding officer at the Alamogordo Army Air Base, in a statement released several hours after the detonation:
Several inquiries have been received concerning a heavy explosion which occurred on the Alamogordo air base reservation this morning.
A remotely located ammunition magazine containing a considerable amount of high explosive and pyrotechnics exploded. There was no loss of life or injury to anyone, and the property damage outside of the explosives magazine itself was negligible.
Weather conditions affecting the content of gas shells exploded by the blast may make it desirable for the army to evacuate temporarily a few civilians from their homes.
That breathtaking bit of public relations came undone when the U.S. announced the attack on Hiroshima on Aug. 6, at the same time acknowledging the test three weeks earlier. The Albuquerque Journal gave prominent play to the local angle in a front-page sidebar headlined "First Test of Atomic Bomb Made at Alamogordo; Explains Explosion There".
The story began: "Persons living in Alamogordo and for hundreds of miles around Monday learned for the first time details of the brilliant flash and explosion that rocked southern New Mexico on July 16. It was the first firing of the atomic bomb."
After recounting the original reports from that day, the Journal noted that "Army secrecy prevailed" when it came to the official story. "Persons seeing and hearing the atomic bomb's flash and roar were puzzled. It was all explained Monday."