Hiroshima Nuclear Bomb – Japan – August 6, 1945

Hiroshima, a city in the south of the main Island of Honshu, was the target in this first use. Most of the buildings were destroyed and 80,000 people were killed instantly.

The first atomic bomb to be used in warfare was dropped on Hiroshima on August 6, 1945. Few knew what the effects would be. There had been only one other bomb of this kind previously detonated. The destruction unleashed on the city was total. About 70 percent of all buildings and 80,000 people were obliterated in an instant.

Why was the bomb dropped on Hiroshima? There are many answers to this question because there were many people involved in the decision. The best estimate of why the decision was taken at that time related to strategic plans. The United States wanted to force Japan’s surrender as quickly as possible in order to reduce American casualties. Alongside that concern was the desire to prevent the Soviet Union becoming involved in the conquest of Japan. Up to that time, the Soviet Union had only attacked and occupied some islands north of Japan. Although an ally of the United States at the time, the dictatorship of the Soviet Union was not trusted by the United States.

Several voices, including that of Dr. Albert Einstein, were raised in opposition on ethical grounds, but they did not prevail. One of these came from Dr. Edward Teller, one of the designers of the bomb. He urged President Truman to drop the bomb high above Tokyo where it would be less destructive but where its destructive power could be felt by the Japanese but without loss of life. That may have seemed like a good idea at the time, but even atomic scientists could not have foreseen then that such an event could have been worse than a direct hit because radiation would have been distributed all over the city of Tokyo and its surroundings.

The history of the bomb tells quite a lot about the harmful influences of dictatorships on scientific research. In the years before World War II, several of the world’s leading physicists, scholars who knew most about how to make an atom bomb, lived and worked in Germany and Italy. As these nations became dictatorships and began to single out Jews for persecution, many of these scholars, fearing they might be targets for attacks by state officials, left their home countries and went to Britain and the United States. One of them, Leo Szilard, who went to the United States along with Einstein in 1940, persuaded Einstein, at that time the most eminent scientist in the country, to write to President Roosevelt proposing a research project to develop an atom bomb.

Roosevelt was not interested at that time. He saw no need for such a weapon, but changed his mind quickly a year later after Pearl Harbor and America’s sudden involvement in World War II. There was good reason for Szilard and Einstein to suspect that Adolf Hitler would attempt to develop an atom bomb. Later, during World War II, Britain discovered that Hitler was busy trying to do that. If he had not changed his country into a dictatorship with terrible murderous policies toward Jews he might have retained the services of the necessary experts and succeeded.

The United States went ahead with a research project for an atomic bomb within a month or two after Pearl Harbor and produced the first successful explosion in July of 1945. It was the costliest military project ever undertaken to produce one bomb. The bomb cost two billion dollars, weighed 4,000 tons, and had the power of 20,000 tons of TNT. The four-year project was located at a new specially constructed lab complex in New Mexico and code-named for secrecy “Manhattan Project.” Both British and U.S. scientists became involved in it. Once there was a successful explosion in the United States, action followed quickly to plan for the dropping of a second bomb over Hiroshima. Individual parts of the second bomb, each encased in a lead container, were shipped one at a time to Tinian Island in the Mariana group of islands.

From there the final flight would be made, a distance of about a thousand miles. In preparation for the flight with the bomb, the bomber crews involved had been doing extensive training and flying both at base in Tinian and in flights over Japan. It was during this period that some uncertainty developed over how best to load the triggering device into the bomb. The pilot of the plane that was to carry the bomb, after consulting with his crew, decided to do the loading while in flight. He reasoned that, if something went wrong, the loss of everything in flight would be better than totally destroying the Island of Tinian. It was a bold decision. Fortunately for him and his crew, the loading of the bomb in flight was successful and they arrived over Hiroshima early on August 6.

There were additional reasons for selecting Hiroshima as the target. The size and the nature of the surrounding terrain made this city suitable for discovering the destructive capabilities of the bomb, critical information that was not known at that time. A second reason was its concentration of military installations, munitions factories, and troop concentrations. There was also the advantage of surprise, an important consideration in a critical bombing mission, since no bombing had previously been carried out there. Hiroshima in August of 1945 was a city of 245,000 people, about 100,000 less than its population at the beginning of the war because many children and others had been evacuated to countryside locations for safety.

Almost all the dwellings were of wood construction, half of them single story and half one and a half stories. Fire-fighting equipment was antiquated but that, like all other public services, mattered little after August 6, 1945. The bomb was dropped around 8:00 A.M. and timed to explode close to the ground. The plane, Enola Gay, was nine miles away when the bomb went off. As the crew looked back at it from 30,000 feet up, and with special protective goggles, one man observed, “We’re looking into hell.”

The day after the bomb, President Truman broadcast news of the event to the United States in words like these: We have captured the energy of the sun in a new and terrible bomb and one of these has already been dropped on Japan. If they do not now accept our demand for unconditional surrender, they may expect a rain of ruin from the air, the like of which has never before been seen on this earth. There was no response from Japan for two days and President Truman decided that the emperor was stalling for time in order to try to arrange something less than total surrender. The reality was quite different.

Protocol in Japan, unfortunately unknown in the United States, because the emperor was seen as God, required a few days for action. The emperor had already decided to surrender but he waited for the military leaders to agree. He knew that they would but not immediately. President Truman decided to launch a second strike. On August 9, Nagasaki was hit with an atom bomb, again from a plane that came from the Island of Tinian. U.S. estimates put the death toll at 35,000 but Japanese authorities later gave it as 87,000.

Everything within the city had been devastated by the bomb and people had to wait for help from elsewhere. For an area of four and a half square miles around ground zero, that is the point on the ground immediately below the bomb explosion, every living person or animal was destroyed. With an atom bomb explosion extremely high pressures and equally high temperatures are present, far greater than are ever experienced in industrial enterprises. The bomb was dropped from a high elevation and timed to go off as it neared the ground. Directly below the bomb everything was vaporized.

The metal framework of one building was all that was left and this became part of a museum that was built later in the center of the city. Beyond the vaporized zone, the supersonic blast of air and heat, releasing millions of degrees of heat, destroyed everything. People standing ten or more miles away were burned right through their skins. They died either immediately or soon afterward. Iron, stone, and roof tiles were twisted out of shape. Clothing, railway ties, and trees instantly ignited. At eight hundred miles an hour of speed and 9,000 degrees of temperature, the hot air created huge swirls of wind that circled back into the city to fill the vacuum initially created. Whatever remained was then destroyed.

The harm done to humans is quite a different story. In 1945, no one knew much about nuclear radiation or the cancerous and other diseases it would generate. Many of the people who were still alive after the bomb had done its work received heavy doses of radiation. Prior to August 6, 1945, there had been more damage and more casualties inflicted on Tokyo by all the bombing raids than was done on Hiroshima by the one bomb. However, the nature of the damage done to humans in Hiroshima was far worse, much longer lasting, and more psychologically harmful. Furthermore, the final death toll directly attributable to the atom bomb was far beyond the 80,000 who died on August 6.

Twenty years after that date the Japanese Broadcasting Corporation announced that the total number of deaths from the atom bomb that was dropped on Hiroshima was 240,000. People standing beside concrete walls when the bomb exploded left a silhouette on the wall. Everything else about them had vanished. Others were burned or cut by flying pieces of metal, wood, or glass. In the months that followed, large numbers of these people died from different illnesses and over a few years many more succumbed. Within two weeks after the bombing, those who had been within five hundred yards of the explosion, even if they were sheltered behind buildings, showed symptoms of deadly radiation sickness, vomiting blood and loss of appetite. Most of them died a week or two later.

By December of 1945 the death toll had risen to 140,000. Over the years since then casualty numbers have continued to mount but statistics are difficult to collect because of health complications additional to those caused by radiation. The special atomic bomb museum that now stands in the center of the old city of Hiroshima carries a detailed, visual documentation of the horror that citizens endured on and after 1945. Many thousands from all over the world visit this memorial annually.

At the present time, the people who were put through the terrible events of August 1945, and their offspring, are more closely monitored than almost anyone else in the world. This is the only place where the effects of radiation on the human body are evident. The relations between levels of exposure and epidemiological conditions are examples of the kinds of things that are measured. From such guidelines for safe exposure to radiation are deduced and employed around the world in the nuclear industry. One scientist believes that almost half a million workers in the radiation industry in the United States and at least that many in Europe have benefited from these guidelines.

There is a major concern about the survivors from the A-bomb as they get older. When they were exposed to the radiation, they suffered damage to their genes, with those closest to the center of the explosion the worst affected. In many cases their genes repaired themselves. It is possible that those repairs were imperfect, making it more likely that they will develop cancer in later life. The highest risk for A-bomb victims developing cancer is among the youngest victims. These people are now approaching an age where they would be more likely to develop a cancer naturally. New genome technology coupled with new methods of diagnosis and treatment offers the possibility of repairing cell damage. It is expected that the number of victims who were young in 1945 will peak in the year 2020 so there is time to develop this approach of cell repair.