On the morning of August 6, 1945, a single aircraft carrying one bomb, flew high over the clear skies of Hiroshima, Japan. The plane had taken off six hours earlier from the island of Tinian, in the Marianas chain, 1,500 miles south-east of Japan. Two other planes were several miles off, there to serve as witness.
On the ground, the people of Hiroshima were starting their work-day. Children had arrived at their schools and adults at their place of business. Hiroshima was an industrial city with a population of approximately 345,000 people. The city also had a large military presence.
On board the aircraft, the pilot started his course over the city, lined up at an elevation of 31,000. At 8:15 am, local time, a bomb descended from the plane and detonated at an elevation of 1,900 feet. Suddenly there was a massive flash of light, many times brighter than the sun, and for an instant, there was no sound…
World War II and been raging for over six years. The most widespread war in human history, it involved over 100 million people and was fought on nearly every continent. It was “total war” where countries threw their entire economic, industrial and scientific capabilities behind the effort. Civilian and military targets were considered one and the same as strategic bombing hit large cities with impunity. In all, an estimated 50-70 million people were killed during the war.
The United Stated entered World War II on December 8, 1941, when President Franklin D. Roosevelt asked Congress for a declaration of war against the Empire of Japan. The day before, Japanese war planes attacked the naval base at Pearl Harbor, Hawaii, killing 2,500 American military and civilians. Eighteen ships in the Pacific Fleet were sunk or run aground, including five battleships, and nearly 200 aircraft were destroyed. Though the attack came as a surprise to most Americans, tensions between the two countries had been brewing since the 1930s, as Japan expanded its hegemony onto China and Southeast Asia. The United States placed economic sanctions on Japan in hopes of slowing down its aggression. Diplomatic discussions had been ongoing, but the two countries had been unable to reach a mutual agreement. On December 7, Japan launched its attack bringing the United States into World War II.
The Manhattan Project
In 1939, prominent physicist, Albert Einstein signed a letter sent to President Franklin D. Roosevelt, urging him to accelerate the research of nuclear chain reactions. The letter warned that nuclear weapons research was being conducted in Nazi Germany. In 1940, the U.S. government began developing its own atomic weapons program. The U.S. Army Corps of Engineers was charged with constructing the vast facilities necessary for the top-secret program codenamed “The Manhattan Project,” so-called for the district where early development took place.
Over the next five years, key components and materials were developed for creating nuclear fission of uranium-235 and plutonium-239. They were sent to the Los Alamos Laboratory in New Mexico, where a team, led by Robert Oppenheimer, worked to develop the atomic bomb. On July 16, 1945, only six years after Einstein’s letter was sent to President Roosevelt, the United States detonated its first atomic bomb with the blast equivalent of 20,000 tons of TNT.
The Decision falls on Harry Truman
President Roosevelt, never lived to see the atomic blast. On April 12, 1945, he died of a cerebral hemorrhage and Vice President Harry Truman became the 33rd President. Truman was not aware of the Manhattan Project until the afternoon of Roosevelt’s death, and didn’t receive a full briefing until June 25th. By the time the A-bomb was tested at Trinity Site at the Los Alamos Laboratory in New Mexico, the Allied powers had defeated Germany. Japan, however, vowed to fight on.
Truman’s team of advisors were split on whether to use the bomb against Japan. Some questioned the morality of using such a powerful bomb and favored a more conventional approach with continued bombing and an eventual ground assault. But military experts estimated such an invasion could cost between 500,000 and 1,000,000 lives. Other advisors proposed a demonstration be arranged to show the Japanese leadership the destructive power of just one bomb, but logistics and the loss of the shock value canceled the proposal. Still others supported the idea of using the bomb. They believed that it’s devastating power would not only convince Japan to surrender, but also place the United States in a dominant position to shape the course of the postwar world.
There were several other pressures weighing on President Truman. On July 26, 1945, during the Potsdam Conference, the Allied leaders issued a declaration outlining the terms of surrender for Japan. At the conference, Soviet General Secretary Joseph Stalin told Truman that the Soviet Union could enter the war against Japan by August 15. According to his diary, Truman hoped the Japanese would surrender before Russia joined the war. Stalin had demanded control of Eastern Europe after Germany’s defeat and Truman didn’t want a similar situation in Asia. In addition, the United States had only two operable bombs at the time and though more were being developed, there was no guarantee a nuclear attack would convince Japan to surrender. Then there was the uncertainty over whether the bomb would detonate from a free-fall drop. The bomb blast at Trinity Site had been stationary. On July 28, the Japanese government rejected the conditions of the Potsdam Declaration and the decision was made to drop the bomb.
As the bomb was being developed, the U.S. Army Air Corps had been conducting training missions with Boeing B-29 Superfortress bombers. Colonel Paul Tibbets was chosen to command the first bombing mission. Tibbets was an experienced combat pilot, having flown 25 missions over occupied Europe, and was in charge of the 509th Composite Group training on the B-29s.
Hiroshima was selected as the primary target for the first attack. The bomb, nicked named “Little Man,” because it was the smaller of the two bombs, was a 9,000-pound uranium-235 gun-type fission bomb. It was loaded onboard a modified B-29 bomber, the Enola Gay, named after Tibbets mother.
On the morning of August 6, at 2:45 am local time, the Enola Gay and its crew of 12 lifted off Tinian Island en route to Hiroshima. Two other B-29s accompanied the Enola Gay, the Great Artiste, carrying instruments to monitor the effects of the bomb and the then-nameless aircraft later called Necessary Evil, to take pictures. The flight took nearly six hours to reach Japan. Enough time for mission commander Captain William S. Parsons to arm the bomb on the plane. At 8:09, upon seeing the target area, Tibbets turned the controls over to the bombardier, Major Thomas Ferebee.
At 8:15 am, local time, the bomb bay doors opened and “Little Boy” made its descent. Tibbets, again at the controls, sharply banked the Enola Gay to avoid being hit by the shock wave. The bomb traveled 44 seconds and then detonated at an elevation of 1,900 feet.
At first there was a massive flash of light, many times brighter than the sun, and for an instant, there was no sound. Then the shockwave expanded out in a wide radius traveling nearly 800 mph. The bomb unleashed the equivalent force of 12-15,000 tons of TNT and instantaneously vaporized thousands of people and nearly all objects in the initial blast area. The destruction raged for five square miles. An estimated 70,000 people were killed due to the blast and another likely 90,000 died in the following months or years due to burns and radiation poisoning.
Astonishingly, the Japanese government did not surrender right away. The Emperor and military leaders were still deliberating over the conditions for surrender. On August 9, Soviet military forces launched an offensive in Manchuria against Japanese troops and declared war on Japan. That same day, another B-29 dropped another atomic bomb named “Fat Man” on the industrial city of Nagasaki. The Japanese surrendered on August 15, 1945.
The legacy of the atomic bomb attack on Hiroshima is mixed. Many claim the bombing was necessary because Japan showed no signs of surrender and an estimated 500,000 to 1,000,000 people might have perished in an invasion. Others feel using the bomb was immoral and that the continued bombing of Japan and the naval blockade would have eventually forced a surrender. What is for certain is that on August 6, 1945, warfare and the world had changed forever.