Gregory M. Franzwa

July 16, 1945, had yet to dawn. Don Hornig, 24, looked over at the baby, "Gadget," in their steel bedroom a hundred feet above the Jornada del Muerto, the "pathway of death" of the covered wagon freighters of the mid-nineteenth century. The tower swayed slightly in the diminishing winds.

The night up there had been horrific—gusting winds, lashing rain, lightning nearby. Thousands of men, from brilliant scientists to army grunts, were stationed on the desert floor in three bunkers, each about six miles from the spindly tower. Floodlights played on the steel room, but Hornig couldn’t see the glare—there were no windows.

Sandra Day, 15, was up early that morning at her dad’s Lazy-B ranch, about 225 miles to the southwest, straddling the New Mexico border northeast of Douglas, Arizona. Ada May and Harry Day had a good-sized spread to take care of, and if they had to arise early every summer’s day, so did their teenaged, freckle-faced daughter. During the school year she lived with her grandmother in El Paso, to attend school. But she was never happier than in the summertime, on the ranch, some twenty-five miles from civilization. It was home.

At 5:10 Hornig’s military telephone rang. The weather was improving. The zero hour had been moved back because of the storm, but it had petered out and the critical moment was now rapidly approaching. He did the final arming operation that he had practiced so many times. Opening the steel door, he took a final look at Gadget, the last man to see it, and started descending the 100 rungs to the desert floor.

The B-29s of Col. Paul Tibbetts’s 509th Composite Group of the Army Air Corps had left their Wendover, Utah, air base in late June, bound for Tinian Island in the Marianas, ten miles long and five miles wide. They were now bombing the Empire of Japan daily with strange looking weapons.

The heavy cruiser USS Indianapolis was steaming toward Tinian from San Francisco at top speed. A metal canister had been welded to the floor of Admiral Spruance’s cabin. He told his officers that, if anything should happen en route, his orders said that the canister was to be saved before anyone, or anything, else. But he had no idea what was in it. "I was told only that every day that we can save on this cruise is a day shorter for this war," he said to his crew. They made the 5,000-mile voyage in ten days.

Zero hour less twenty-four minutes and forty-five seconds. Hornig had sped away in his jeep. At zero hour less twenty minutes forty-five seconds, the automatic timers took over. At zero hour minus forty-seconds a more precise timer clicked in. The only man on earth who could stop the process now was Don Hornig, now safely in a bunker six miles away, a switch at his side.

Harry S Truman, president of the United States for the past fifteen months, was meeting with two other heads of state in Potsdam, southwest of Berlin in defeated Germany. With Winston Churchill, he was trying to bridge the impossible gulf between the free world and the totalitarian world of their ally, dictator Josef Stalin. But Truman was smiling inwardly. He knew something Stalin didn’t know. Or so he thought.

The men in the bunkers were lying on the ground now. Most didn’t know what to expect, but they were taking no chances. Enrico Fermi, the swarthy, balding nuclear scientist from Rome, only 43 but already at the top of his game, was convinced that New Mexico was forty-five seconds from being vaporized. The tall, spindly, project manager, Robert Oppenheimer, gnawed on his pipe stem, so nervous that he had to lean against a bunker support to keep from falling over. At zero less forty-five seconds he joined portly Gen. Leslie Groves prone, on the ground, feet toward that distant tower, and donned glasses so dark that he could see nothing at all.

At 5:29:35 A.M. the countdown continued over the public address systems at each of the three bunkers—"ten, nine, eight…" The justification for the staggering expense of the enormous gaseous diffusion plant at Oak Ridge, Tennessee, hung in the balance. Would the millions spent on the plutonium plant at Hanford, Washington, be wasted? Would two years of around-the-clock effort at Los Alamos, New Mexico, by some of the world’s most noted physicists, come to naught? Would the invasion of Japan proceed on schedule in four months? Would the lucky thousands of the young men who somehow had managed to survive the war in Europe meet their ends on the beaches of Honshu?

"three, two, one . . ."

Some scientists thought that they had some idea of what to expect. But they had no idea. The Gadget exploded with a force of 21,000 tons of TNT. The flash raced six miles to the bunkers in less than a second, with an eerie silence. "The whole country was lighted by a searing light with the intensity many times that of the midday sun," remembered Gen. Thomas Farrell. "It was golden, purple, violet, gray, and blue. It lighted every peak, crevasse, and ridge of the nearby mountain range with a clarity and beauty that cannot be described."

The witnesses stared wide-eyed through their smoked glasses at the brilliant fireball. "It looked like a giant magnesium flare," wrote scientist Hans Bethe, "which kept on for what seemed a whole minute but was actually one or two seconds. The white ball grew, and after a few seconds became clouded with dust whipped up by the explosion from the ground."

The dark glasses came off, but the men wisely remained prone. About six seconds after the flash came a blast of hot air, just ahead of a cacophonic roar—the same sound as a nearby lightning strike, only sustained. Oppenheimer said that he was reminded of the quote from Bhagavadgita, "I am become Death, the Destroyer of Worlds." Profound, yes. But then he wrote to his brother, Frank: "It worked."

Sandra Day remembered coming downstairs for breakfast when she heard a strange boom—she had never heard anything like it. Down in El Paso, still farther away, some windows cracked. People in the dusty little town on the lower Colorado, Las Vegas, wondered about it, too. The government issued a bulletin—a small munitions dump had exploded, that’s all.