On the following day, having scanned the weather forecast, LeMay gave the word: the mission was on for the 6th. Little Boy was taken from the 509’s air-conditioned assembly hut and pulled gently, by a tractor, to a pit on the runway. Several of the men had written messages on the bomb with crayons. Some were obscene missives for the Japanese, but Major John E. Moynihan, the public-relations officer for the mission, wrote, ‘No white cross for Stevie’—his young son at home. The bomb was loaded into the pit, and the annointed bomber, No. 82, was towed over it. The bomb was winched into the plane’s forward bomb bay and secured with a central shackle and several braces. The loading went smoothly. Meanwhile, Tibbets had decided his plane needed a name. He summoned from a base softball game a sign painter and instructed that ‘Enola Gay’, his mother’s first and middle names, be painted on the fuselage. The bomber’s usual pilot, Robert Lewis, was unhappy to discover the change, but Tibbets was now in charge and anyway the paint had already dried. Lewis would serve as Tibbets’s co-pilot on the run to Hiroshima.
The plan called for Deke Parsons to ready the bomb while the plane remained on the ground, inserting into its rear end the explosive and the detonator that, once activated, would fire it off, sending the uranium bullet home. Parsons had wanted to perform this operation once the plane was in flight, but Groves, worried about turbulence and the tiny space in which Parsons would have to work, said no. Parsons had accepted the verdict— until he saw the alarming rate at which B-29s taking off from Tinian’s Runway A, the one to be used by the Enola Gay, had crashed short of liftoff. A crash with a nuclear bomb on board might obliterate Tinian. Now he confided in Farrell: he would do the final bit of assembly only after the plane was airborne. Farrell cautiously consented, and Parsons folded himself into the tiny space behind Little Boy and practiced inserting the charge until his hands bled. Farrell offered Parsons a pair of gloves, but Parsons refused; ‘I’ve got to feel the touch,’ he said. By the time Farrell did his duty and cabled Groves about the important change in procedure, there was nothing Groves could do but ratchet up an already serious case of nerves.
They would take off at 2.30 the next morning, 6 August. Men tried to sleep but mostly failed. The final briefing came at midnight, where Tibbets blandly repeated his description of the bomb they carried as ‘very powerful’, and the Lutheran chaplain on base prayed with the crew that ‘they bring this war to a rapid end’. The men had an early breakfast of eggs, sausage, and pineapple fritters, a favorite of Tibbets. They were driven to their B-29s at 2.00 and arrived to a cacophony of sound and harsh lights worthy of a Hollywood movie set (thought an unhappy Tibbets) or, as someone else put it, ‘a drugstore opening’. Photographs were taken of the Enola Gay’s crew, after which they climbed into their plane. The men all had pistols, and Tibbets secretly carried a metal box holding twelve cyanide capsules; if the plane went down over Japan, any crewman left alive would choose suicide by self-inflicted bullet or self-administered poison. ‘Let’s go,’ said Tibbets at 2.45, and he throttled his plane forward. It was heavy, some 15,000 pounds over spec with its weighty bomb and extra fuel, and Tibbets badly frightened co-pilot Lewis by using nearly all of Runway A to gain speed. At what seemed the last second Tibbets lifted the plane’s nose, and the Enola Gay rose over the night sea, flying northwest at low altitude to save fuel and ease the task of Parsons, squatting behind the bomb in the unpressurized bomb bay.
Parsons inserted cordite charges into Little Boy’s back end, but he left a key circuit undone so the bomb was not yet armed. Tibbets tried to sleep, failed, and chose instead to disclose at last the full truth about their payload. The sky grew lighter, indicating fair weather ahead. Just before 6.00 (5.00 in Japan) they reached Iwo Jima, where Tibbets climbed to 9,000 feet and rendezvoused with the Great Artiste and No. 91, the instrument and photo planes. Parsons and his fellow weaponeer Morris Jeppson finished arming the bomb. ‘It won’t be long now,’ said Tibbets over the intercom. The Straight Flush, the B-29 that overflew Hiroshima, sent word that the skies over the primary target were largely clear, so Tibbets committed to his course and brought his plane to bombing altitude, 31,000 feet. The crew, though not their pilots, put on flak suits, and all drew on smoked-glass goggles to protect their eyes from they knew not what. Bombardier Ferebee spotted the target and took charge of the Enola Gay’s course for the bombing run. The other two planes slowed and let the Enola Gay run to the target alone. Ferebee saw the Aioi Bridge. ‘I’ve got it,’ he called. Then, just after 8.15 Hiroshima time, the bomb-bay doors opened and the bomb tumbled out. Ferebee later said he could see it turn its nose to the ground, as it was supposed to. Free of its load, the Enola Gay leaped up. Tibbets’s months of training took over, and he dived and sheared off, speeding frantically away from the blast area. The bomb’s proximity fuse was set for roughly 1,850 feet above the ground, which meant that the bomb should explode 43 seconds after it had left the bomb bay. Jeppson was counting it down. He got to 43—nothing. ‘It’s a dud,’ he thought. Then an intense light lit the plane, followed by a powerful jolt. It felt, recalled the navigator, Dutch Van Kirk, as though he had been sitting on a metal garbage can that someone had hit with a baseball bat. Tibbets first thought it was flak. Then came a second blast wave, and the pilot calmed down; he knew what it was, and that there would be no more.
They saw the fireball, then the mushroom cloud that Parsons had told them about during the briefing ages before. ‘The city was hidden by that awful cloud,’ Tibbets wrote later, ‘boiling up, mushrooming, terrible and incredibly tall.’ ‘A column of smoke is rising fast,’ said the tailgunner, Robert Caron, into a voice recorder. ‘It has a fiery red core... Fires are springing up everywhere... there are too many to count.’ Tibbets radioed Tinian that the bomb had produced ‘good results’, which staggered Deke Parsons: ‘ “Good”? Hell, what did he expect?’ On his own, he wired Farrell that the visual effect of the bombing had been ‘greater than [at] Alamogordo’. Jake Beser, in charge of preventing Japanese jamming of the mission’s communications, likened the sight to sand stirred in shallow water at the beach; Robert Lewis thought the cloud resembled ‘a pot of boiling black oil’. Lewis gave silent thanks that his war would soon be over, but the displaced pilot of No. 82 had other thoughts too: ‘My God,’ he wrote in his journal, ‘what have we done?’ ‘If I live a hundred years,’ he added, ‘I’ll never quite get these few minutes out of my mind.’19
The Enola Gay and its escort planes headed for home. They lost sight of the mushroom cloud only after 363 nautical miles. Many of the men on Tibbets’s plane now slept, exhausted. Aboard the Great Artiste, the physicist Luis Alvarez, who had monitored the blast in part by dropping instrument-bearing parachutes simultaneously with Little Boy, grew pensive, and decided to write his ‘first grown-up letter’ to his 4-year-old son, Walter. ‘What regrets I have about being a party to killing and maiming thousands of Japanese civilians this morning’, he wrote, ‘are tempered with the hope that this terrible weapon we have created may bring the countries of the world together and prevent further wars.’ As the planes approached Tinian, Charles Sweeney slowed his craft so that Tibbets would have the honor of landing first. No one threw stones at the 393rd crews as they clambered down from their planes; the men were greeted instead as arriving heroes.20
President Harry S. Truman was then in the North Atlantic, aboard the cruiser USS Augusta on his way back to the United States from Potsdam. He had already let slip to the ship’s officers and crew that their country had tested a powerful new weapon—like those briefing the crews on Tinian, Truman had not used the word ‘atomic’—calling it ‘the biggest gamble in history’ but one that might by itself end the war. The President got news of the Hiroshima bombing in the form of a twenty-six-word message, soon supplemented by one somewhat longer. He was at lunch with six enlisted men when an aide handed him the bulletins. Grinning broadly, Truman gripped the captain’s hand, and declared: ‘This is the greatest thing in history!’ He announced to the crew that ‘an atomic bomb’ had been dropped on a Japanese city, then strode off to the officers’ mess to repeat the news. ‘It was an overwhelming success,’ he told the men. ‘We won the gamble!’ In the meantime Leslie Groves, who had waited anxiously for word of the attack (he eventually received Parsons’s message to Farrell, delayed by a communications’ glitch), had released an official presidential announcement about the bombing. Unsure yet about the impact of Little Boy on its target city, Groves described instead its power, slightly overestimated, on the basis of the Trinity shot, at 20,000 tons of TNT. ‘It is an atomic bomb,’ the announcement went on. ‘It is a harnessing of the power of the universe.’ Groves described Hiroshima as ‘an important Japanese Army base’.21