I Am Become
The June 1945 Atomic Bombing of Hiroshima and Kokura
By Chris Oakley
(based on the series "Sic Semper Tyrannis Germaniae" by the same author)
Since their inception in the early 1940s, the objective of the Manhattan Project and its British counterpart Tube Alloys had been to produce an atomic bomb for the Allied powers before the Nazis got one first. But everything changed on July 20th, 1944 with the the assassination of Adolf Hitler; his death not only tore the heart out of the Third Reich, it threw the German war machine into total disarray just as the Anglo-American liberation of France and the Soviet campaign in Poland were both starting to pick up steam. By December the Nazi empire was in the final stages of collapse and and the provisional German government would be suing for peace. With Germany defeated and Italy having come back to the Western fold after the 1943 overthrow of Benito Mussolini, only one Axis power remained to be dealt with: Japan.
As Eisenhower’s armies were preparing to initiate their final attack on Berlin, Manhattan Project director General Leslie Groves and his top scientist, Dr. J. Robert Oppenheimer, flew to Washington for a closed-door meeting with President Roosevelt on reassessing the project’s goals. They said, and Roosevelt agreed, that henceforth the uranium bomb should be given top priority over the plutonium bomb since it was easier to produce, had more destructive power, and was more likely to be ready for deployment by the projected time frame of the summer of 1945.
When Groves and Oppenheimer returned to the Manhattan Project’s headquarters in Los Alamos, New Mexico, they brought with them a signed directive by President Roosevelt stating that all work on the plutonium bomb was to be suspended until mid-July of 1945. A prototype of the uranium bomb was scheduled to be test-detonated in early March; the experiment, code-named "Trinity", would be carried out under Dr. Oppenheimer’s direct supervision.
There was naturally some disappointment among those who felt the plutonium bomb should have remained the Manhattan Project’s number one priority, but the grumbling subsided as Oppenheim’s team became caught up in the race to get the Trinity test site preparations done in time for the March 1945 experimental detonation. General Groves kept the White House apprised of the progress of their preparations via encrypted cables sent directly from his office. U.S. Army Air Corps chief of staff General Henry H. "Hap" Arnold began drawing up a list of possible targets for the first A-bomb strike on Japan.
A lot was riding on the success of the Trinity test. For one thing, there was a simple need to satisfy human curiosity; having put so much time and energy into the bomb’s development, General Groves reasoned, they might as well go the rest of the way and find out if the damned thing worked or not. Second, President Roosevelt wanted a sure-fire deterrent to Soviet expansionism; since the final surrender of Germany he’d finally started to have doubts regarding Stalin’s intentions in eastern Europe, and if worst came to worst he thought the bomb might offer a means of discouraging the Red Army from moving into western Europe.
But by far the most important consideration guiding Roosevelt’s policy on the atom bomb was that the new weapon promised a quick end to the Pacific War. The Allies’ only other option for bringing about Japan’s final defeat was an invasion of the Japanese home islands that not only threatened to inflict horrific casualties on both sides, but also had the potential to push the war well into the summer of 1946. While American warplanes had been bombing known and suspected kamikaze bases in Japan since February of 1945, there was still the chilling prospect that suicide attacks could cause severe losses among American troops.
By late February of 1945 all the necessary ingredients were in place for the Trinity test. On March 3rd, Dr. Oppenheimer assembled his staff at an observation post near Alamagordo, New Mexico to record the first controlled atomic explosion in human history; prior to the detonation it was estimated that the force of the blast would equal anywhere from 5000 to 9000 tons of TNT. The final countdown to detonation began at 5:40 AM local time; five minutes later, the loudest man-made blast ever recorded ripped through the New Mexico air and a massive fireball lit up the desert morning like a second sun.
As the fireball rose into the sky, Oppenheimer and his colleagues thanked their lucky stars for the protective goggles they were all wearing against the explosion’s glare as well as for the observation post’s concrete walls, which shielded them against flying debris and the blast wave from the explosion. The sight of the colossal mushroom cloud prompted Dr. Oppenheimer to think of the famous apocalyptic Bible verse Revelations 7:12: "And I opened the sixth seal...and behold there was a great earthquake, and the sky became black like sackcloth, and the moon became like blood."
When the last echoes of the explosion had faded away, Oppenheimer and his colleagues checked the data from their seismometers; to their individual and collective astonishment, the force of the blast had equaled not 5000, not even 9000, but 20,000 tons of TNT. If anyone at Los Alamos had held the slightest shred of doubt the atomic bomb was a powerful destructive force, that doubt was now well and truly dead.
Two weeks after the Trinity test, the US Army Air Corps ordered the Tinian Island-based 509th Composite Group to begin what they modestly referred to as "special training". This bland description belied the incredible magnitude of the job the 509th’s crews were being asked to prepare themselves for; they’d been entrusted with the dangerous task of conducting the first nuclear bomb attack in human history, and that was not something to be taken lightly. Few men understood this better than the 509th’s commanding officer, Colonel Paul W. Tibbetts. As a veteran of the 1942-44 American bombing campaign in Europe, he was well-suited to take on his new responsibilities; he took the "special training" very seriously and exhorted those under his command to do likewise.
For security reasons, the officers and men of the 509th were banned from discussing the nature of their mission with outsiders or even among themselves. However, there was no shortage of other topics for conversation; much of the men’s downtime in between training flights was spent discussing items like postwar plans, the Verona war crimes trials in Italy, the upcoming baseball season, and the growing tension between the western Allies and the Soviet Union over the future of Germany.
The list of potential targets for the 509th Group’s first A-bomb attack was as notable for the cities that weren’t on it as for the cities that were. By direct presidential order Tokyo and Osaka, the two largest urban areas in Japan, were placed off-limits to atomic bombing; Tokyo was the seat of government and therefore had to be left intact to permit negotiation of a final surrender, while Osaka was adjacent to a proposed landing zone for the invasion of the Japanese home islands, which Roosevelt feared the Allies might yet have to carry out if his nuclear gambit didn’t work.
At the top of the target list were the ports of Hiroshima and Kokura and the manufacturing center of Nagasaki. Hiroshima was of particular significance, given that its naval base had been the starting point for the attack on Pearl Harbor that had officially made the United States a combatant in the Second World War. Seen in that light, an A-bomb strike on Hiroshima could be viewed as a kind of retribution for the attack. Roosevelt had far more prosaic reasons for putting it at the top of the list, however; he wanted to eliminate the marines stationed at its naval garrison as a threat to U.S. troops.
However, it wouldn’t be FDR who made the final decision about where to drop the first A-bomb; he died of a cerebral hemorrhage on April 16th, 1945, just over a month after the Trinity test. The responsibility was thus conferred on his predecessor and former Vice-President, Harry S. Truman, who wasn’t even aware of the bomb’s existence until the day after he was sworn into his new office. By then, modifications were well underway on the B-29s that were assigned to make the first atomic strikes against Japan.
The first B-29, to be flown by Colonel Tibbetts himself, was dubbed "Enola Gay" after Tibbetts’ mother; the second, nicknamed "Bock’s Car", would be piloted by one of Tibbetts’ squadron commanders, Major Charles W. Sweeney. Both B-29s would each be accompanied on their respective bomb runs by a weather reconnaissance aircraft and, as they approached the Japanese coastline, escort fighters operating from airstrips on the US-occupied island of Iwo Jima. Once the B-29s conducting each of the first two atomic strikes had unloaded their lethal cargo, they would turn for home, flying at maximum speed to avoid getting caught in the shock wave of the explosion when the A-bombs detonated.
Truman agreed with Roosevelt’s earlier decision to put Hiroshima at the top of the atomic hit list but reversed Nagasaki’s and Kokura’s places on it, dropping Kokura to number three and bumping Nagasaki up to number two, reasoning that Nagasaki as a major industrial center was the more important of the two towns and thus should be accorded a higher priority.1
The first atomic raid on Japan was set to take place no later than July 20th, 1945, the one-year anniversary of Hitler’s death. President Truman chose this date for both practical and symbolic reasons. On the symbolic side of things, he and his advisors saw this raid, and the ones to follow, as a means of hammering the final nails in the coffin of the Axis; in more practical terms, the White House sought to ensure that they not only deterred the Red Army from carrying out a planned assault on Hokkaido but also left themselves plenty of time to give the ‘go’ order for the American invasion of the home islands, code- named Operation Olympic, should such landings prove to be necessary after all.
Also factoring into this choice was a desire to make certain the Manhattan Project’s uranium processing plant in Oak Ridge, Tennessee had adequate time to begin preparing the material for a third atomic bomb if one were called for. Turning raw uranium into weapons-grade material is a hard, time-consuming process2, and Truman wanted to be sure he left himself plenty of time for that process to be completed.
The directive officially designating Hiroshima as the primary target for the first atom bomb raid was issued by Hap Arnold and countersigned by Joint Chiefs of Staff chairman General George C. Marshall on May 17th, 1945; two weeks later, the bomb that would be used in the attack, code-named Little Boy 1, was delivered in secret to Tinian along with its cousin Little Boy 23 on board the cruiser USS Indianapolis.4
On June 7th, as the United Nations Charter Conference was convening in San Francisco, Col. Tibbetts learned via coded cable that he was to carry out the Hiroshima strike in ten days’ time; if the Japanese didn’t surrender following that attack, Maj. Sweeney’s aircraft would drop the second A-bomb four days later. Both pilots and their crews went through one last round of intensive training as the day for the Hiroshima strike drew closer; on June 15th, two days before the nuclear attack, Tibbetts and the crew of "Enola Gay" conducted a final debriefing to review their flight plan for the raid.
On the other side of the Pacific the citizens of Hiroshima, like millions of their compatriots throughout Japan, were preparing to defend their homes against an American invasion force, not realizing the scientifically engineered hell that was about to be visited on them...
It was still nighttime on America’s East Coast when "Enola Gay" took off from Tinian with its accompanying weather recon plane on June 17th, 1945; in Japan, on the other hand, it was approaching 12 noon. But whatever time zone one was in, the clock was steadily ticking toward the dawn of the nuclear age. In addition to the usual pre-flight anxiety common to both military and civilian aviators, Colonel Tibbetts and his crew were also experiencing nervousness about the possibility that mechanical problems might cause the bomb to go off prematurely before they reached Hiroshima. But they didn’t let fear of any kind affect them-- the way they saw it, they had a job to do and they were determined to see it completed.
Strictly speaking, it wasn’t actually necessary for fighters to go along with "Enola Gay" on the final leg of its journey to Hiroshima; Japan’s once-formidable air power had, for all practical purposes, long ago ceased to exist except for a handful of kamikaze units making last-ditch attacks against the Allies. But General Curtis LeMay, the overall C-in-C for US Army Air Corps bomber forces in the Pacific, wasn’t taking any chances; some hotshot who wanted to die for the Emperor could still throw a monkey wrench into the works if he were able to find and ram Tibbetts’ plane, and LeMay wasn’t about to let that happen.
It was 1:30 in the afternoon Tokyo time when "Enola Gay" reached its target; the chosen aiming point for the bomb was the Genbaku Dome Exhibition Hall, which before the war had been an industrial display center. In addition to the weather reconnaissance plane, Tibbetts’ bomber was accompanied by a photo reconnaissance aircraft assigned to keep cinematic records of the A-bomb strike and its aftermath.
At 1:35 Colonel Tibbetts gave his bombardier the "go" signal to drop the bomb. To allow the B-29 maximum time to get clear of the target before the bomb detonated, Little Boy 1 was rigged with a mini- parachute that would open and slow the bomb’s descent after it cleared the bomb bay. Once the bombardier confirmed the bomb’s release, "Enola Gay", the weather and recon planes, and the fighter escorts all turned for home as fast as their engines could manage.
Seven minutes later the city’s air raid sirens gave the "all clear" signal and Hiroshima’s residents, erroneously thinking they were out of danger, began to emerge from their bomb shelters. They stared in curiosity and disbelief at the small object drifting slowly down to the roof of the Genbaku Dome, uncertain what to make of it; at that point, "Enola Gay" and her escorts were already dashing hell-for- leather back towards the Japanese coast, eager to get clear of the bomb blast and be on their way home before Little Boy 1 detonated.
"Enola Gay"5 was about halfway to the Japanese coastline when her tailgunner noticed a bright flash on the horizon. "My God!" he heard one of his crewmates gasp, and he realized why when he saw a towering mushroom cloud looming up into the afternoon sky like an angry demon.
What he was seeing, from a distance, was the detonation of Little Boy 1’s U-235 warhead a few hundred feet above the roof of the Genbaku Dome. No one who was in Hiroshima that day and survived the bombing would ever forget the moment-- the hellish roar of the explosion itself, the crushing force of its blast wave, the blinding light that glared from its center like a supernova, the heat which was intense enough to melt solid rock.
Mere milliseconds after the bomb detonated, a firestorm of nearly apocalyptic proportions began sweeping over Hiroshima; since most Japanese buildings at that time were constructed of flammable material like timber or paper, the conflagration’s rapid spread from the impact point to the rest of the city was practically inevitable. Those still inside bomb shelters the A-bomb exploded were incinerated alive as the winds of the firestorm turned those shelters into crematoriums.
The most damaging effects of the bombing, however, would take weeks to surface; though they didn’t know it at the time, many of the survivors of the horrendous event had been subjected to massive doses of radiation from the uranium in Little Boy 1’s warhead, and in the aftermath of the bombing some of these people would die as a result of the cellular damage those doses had inflicted on their bodies.
The death toll from the bombing itself exceeded 80,000; tens of thousands more would die from their burns and injuries by the time the Pacific war was over. And in the years after Hiroshoma, thousands of others would succumb to the previously little-known peril of radiation poisoning.
And Hiroshima would not be the only city to meet this tragic fate...
To Truman’s dismay, the Hiroshima A-bomb strike proved to be insufficient in forcing Japan’s surrender, and so the second A-bomb strike was scheduled for June 23rd. The mission profile for this attack was roughly similar to that of the first, except that this time there would be an extra escort fighter accompanying the bomber to its designated primary target. General LeMay was just as concerned about kamikaze action on this bomb run as he had been when "Enola Gay" had taken off for its raid on Hiroshima.
"Bock’s Car" departed Tinian at 10:30 AM Tokyo time on the morning of June 23rd; at 11:15, Charles Sweeney and his crew received word that a partial cloud cover had formed over their primary target, Nagasaki. Rather than abort the bomb run, Major Sweeney opted to redirect his flight path towards the raid’s secondary target, Kokura.
Little Boy 2 was dropped at 12:15 PM, five minutes after the first air raid sirens had blared in Kokura; like the first Little Boy, this bomb’s descent towards its designated aiming point was slowed by a parachute to allow the bomber time to get to safety. Sweeney’s B-29 had just reached the Suo Sea coast and was completing its final turn for home when the bomb detonated, inflicting the same cataclysm on Kokura that Hiroshima had suffered six days earlier.
110,000 people, many of them refugees from the Hiroshima A-bomb strike, were killed in the nuclear attack on Kokura. Realizing that further resistance to the Americans could only bring catastrophe, Emperor Hirohito authorized his foreign minister Mamoru Shigemetsu to notify the American, Soviet, and British governments that Japan would unconditionally surrender to the Allies at once. The emperor made his decision just in the nick of time-- though he didn’t know it, a third specially modified B-29 had already arrived at Tinian and its crew was making tentative preparations for a third A-bomb strike in early July, this time on Sapporo.6
At 8:00 PM on the evening of June 23rd, Hirohito made a radio address to his fellow countrymen to officially announce the surrender. For many of them, it would be the first time they had ever heard their emperor’s voice-- and his words would break their hearts. In somber tones which reflected the sorrow Hirohito himself felt at that moment, the emperor asked his subjects to "endure the unendurable" for the sake of Japan’s future.
A group of extremist army officers tried to thwart the surrender by breaking into the Imperial Palace during the broadcast and seizing Hirohito and his cabinet, but their coup attempt was foiled by the emperor’s palace guards. From then on, all that remained was the formal signing of the surrender agreement between Japan and the Allied powers; that took place on July 2nd, 1945 in Tokyo Bay on board the battleship USS Missouri.
The atomic bomb would prove a useful trump card for the Truman Administration during the Berlin crisis of 1947-48, when Soviet dictator Joseph Stalin threatened to launch an invasion of western Europe in retaliation for an alleged Western plot to cut off Soviet access to the eastern sectors of the former capital of the Third Reich. Faced with the prospect of nuclear strikes on Moscow and Leningrad(present-day St. Petersburg), Stalin eventually backed off from his invasion threats and the Soviet Union signed an agreement with the Western powers that guaranteed all four nations occupying Germany unrestricted access to their occupation zones inside Berlin.
But the American monopoly on nuclear weapons would come to an end in February of 1949 with the test detonation of the first Soviet A- bomb at a remote location in Siberia. Within the next decade, Great Britain and France would have their own nuclear capability; by the early 1960s China had built its first A-bomb; India would join the nuclear club in 1974(though would not admit to doing so until the late 1990s); Israel and South Africa would secretly establish atomic weapons programs during the early 1980s; and Pakistan would set off its first experimental atomic bomb by 1998.
Though the threat of a direct nuclear confrontation between the United States and Russia has diminished a great deal since the USSR collapsed in 1990, nuclear terrorism is still a grave security concern among the world’s major powers today. And with Iran, North Korea, and Argentina all trying to achieve their own nuclear weapons capabilities, there can hardly be any doubt the Pandora’s box which was opened on that June day in 1945 still has not yet been closed.
1Here is another, though lesser-known connection between the A-bomb strikes and the attack on Pearl Harbor-- it was a Nagasaki factory that manufactured the bombs and torpedoes used by Nagumo’s strike force on December 7th, 1941.
2Just ask the North Koreans.
3The weapon to be used in the second atom bomb attack.
4It would turn out to be her final operational assignment; three days later, in one of the most tragic "friendly fire" accidents of the Second World War, she was torpedoed and sunk by a US Navy submarine that mistook her for a Japanese destroyer, taking her entire crew with her. The captain of the submarine responsible for the disaster was subsequently relieved of his command, court-martialled for incompetence, and dishonorably discharged from the US Navy; he died of alcohol poisoning less than a year after the war ended.
5Named after its original pilot, Major Frederick C. Bock.
6The Sapporo mission was immediately cancelled upon confirmation of Japan’s surrender to the Allies.