Nuclear explosion in Hiroshima: details and facts

One of the most tragic events, that happened during the World War II is Nagasaki & Hiroshima bomb blast, which took place on August 6th and 9th, 1945, respectively. It was already the final stage of the war, and these two bomb blasts have killed over 129.000 people. It is curious, that these actions up to the present remain the only case, when nuclear weapon was used by a country in terms of warfare.

Before the nuclear bomb blast in Hiroshima and Nagasaki, the American firebombing campaign managed to destroy 67 Japanese cities, and as a result of all these actions many civilians and Japanese soldiers died. So what were the presuppositions of these actions and what exactly lead to such serious consequences and deaths? Let us start from the very beginning.

Background and premise of bomb blast on Hiroshima and Nagasaki

During the final stage of the World War II (1945), there took place a Pacific War, and the Empire of Japan fought in order not allow American victory in the war. However, due to certain warfare actions, which influenced the fleet, loss in shipping influenced the fishing and agricultural segments of Japan, and strongly undermined the economy of this country. In certain areas, there was even malnutrition and hunger.

From the political point of view, there was strong opposition between the Allies and Japan. It is fair to say, that invasion of Japanese islands was extremely costly to the U.S., and certain steps were taken to conquer the country and gain the victory in the lasting battle.

1. Between April, 1942, and August, 1945, there took place a serious U.S. firebombing campaign, and as a result, there was destroyed around 67 Japanese cities and thousands of people were killed.
   2. The Japanese decidedly refused to accept the offer for surrender of the Allies.
   3. As a result of this refusal, the United States, supported by the United Kingdom and China, offered the only possible option, the prompt destruction if the surrender is refused.
   4. The response to the ultimatum was completely ignored by Japan, so the Allies kept the promise and started preparation of the nuclear weapon to be further used in Japan.

Bomb blast of Hiroshima and Nagasaki: preparation and explosion

After the refusal of the Japanese to sign the unconditional surrender, as demanded by the Allies, there followed a strict ultimatum. According to it, if Japanese ignore or refuse to sign this agreement, ‘prompt and utter destruction’ will follow as a result. This alternative was offered to Japan on July, 1945, and was completely ignored. So, in July, the armed forces of the Allies started preparation of the weapon for Japan.

In July, 1945, U.S. armed forces conducted a probing detonation of the atomic bomb in desert in New Mexico, and started development of two similar bombs for the attack towards the Japanese. Also, they assembled a special plane, the Boeing B-29 Superfortress, which was capable of delivering the bomb to the destination. So, the first bomb of uranium gun-type, known as the ‘Little Boy’, was dropped on Hiroshima, and in 16 hours Harry S. Truman again called for the surrender.

The second bomb blast followed three days later, on August, 9, and it was the plutonium bomb, colloquially nicknamed as the ‘Fat Man’. It was dropped on the second port city, the Nagasaki. And while the largest number of deaths in Nagasaki were the civilians, in Hiroshima there was located a large military garrison of the Japanese, so the army faced serious personnel losses.

Hiroshima atom bomb blast: characteristics of the weapon and explosion

To attack Hiroshima, Los Alamos Laboratory (U.S.) built a uranium-based bomb, which was produced in 1945. It is nicknamed as the ‘Little Boy’. The bomb was dropped to Hiroshima back on August, 6, 1945, by means of a plane, piloted by Colonel Paul Tibbets. This bomb was the first nuclear bomb in the history, that was used in warfare. Here are some specifications of this weapon.

• Weight of the bomb equals to 4.400 kg (9.700 lbs);
• Length is 3 m (10 ft);
• Filling of the bomb is radioactive Uranium 235;
• Weight of the pure filling in the bomb is 64 kg (140 lb);
• Strength of blast equals to 15 TNT kilotons.

It is curious, that there was built 36 units of this weapon, and all of them were withdrawn from the service in 1951, with the exception of one atom bomb, which was used against Hiroshima. So, Hiroshima bomb blast took place around 8.15 AM local time, and the bomb exploded at the height of around 1.900 feet above the ground. Detonation of the bomb was caused due to barometric trigger, which started the mechanism when the altitude rapidly changed.

If we compare power of the Little Boy with the Fat Man, dropped on Nagasaki three days later, it is vivid, that despite of significantly less powerful filling, the number of victims in Hiroshima was way higher. This is all due to the geographical positions of the cities, since Hiroshima was located on flat surface, and the Nagasaki bomb got into a small valley.

Right after the bomb blast in Hiroshima, President Truman officially announced the yield of the bomb as 18 kilotons, and the media rounded it to 20. Later on, after a survey, conducted by the Manhattan Project, it was calculated, that the yield of the Little Boy equaled to 12 kilotons. And the latest researches show slightly different figure, equivalent to 13 kilotons of TNT.

Hiroshima Nagasaki bomb blast: deaths, injuries and losses

Hiroshima Nagasaki blast lead to very serious consequences, as many people died, got injured and obtained serious health issues. As a result of Hiroshima explosion, 66.00 people were killed immediately right after Hiroshima bomb blast. 69.000 people got different degrees of injuries, and some from them also died. Of the overall number of deaths, 20.000 were the soldiers and officers of the Japanese Imperial army, since in Hiroshima there was located a large military garrison. The overall number of deaths, according to different sources and studies, ranges between 90.000 and 146.000 of military and civilian people.

According to the technical characteristics of the nuclear weapon used by the Allies against these two Japanese cities, the bomb used in Nagasaki was way more powerful, than the one, which caused Hiroshima explosion. Nevertheless, due to landscape differences in these areas, Nagasaki explosion caused less death, with the number ranging between 39.000 and 80.000. During the Nagasaki blast, the majority of people killed were civilians, with very small number of military officers and soldiers.

Nuclear explosion Hiroshima experienced negatively caused health state of the citizens months after the blast. As a result, many people died later on, as a result of radioactive environment influence. The main reasons of these deaths were caused with the following factors:

• Nuclear sickness;
• Radiation effect;
• Malnutrition and poor environmental condition in the area;
• Burns of different degree;
• Blood poisoning.

The main cause of the immediate deaths in Hiroshima is burns, so around 60% of victims died due to this reason. Around 30% of the deaths were called with the falling buildings and certain other debris. And only 10% of deaths are due to high radiation dosages, flying glass and some other reasons.

Hiroshima and Nagasaki blast. Lethal weapon, way more powerful than regular explosions

Hiroshima Nagasaki bomb blast became a powerful attack, which caused extremely serious physical damages to these Japanese cities, and killed millions of people. Besides, it caused serious impact to the environment in this areas, so that they would be effective decades after the Nagasaki and Hiroshima nuclear blast. It is fair to say, that nuclear blast is the most powerful attack the Allies could choose. Why?

• First. A downward pressure effected means of communication, flat roofs and overall made the explosion that powerful. The vertical poles and telegraph pillars, which were located right under the explosion, remained undamaged, though the objects at bigger distances were hit with the wave. As a result of this destruction power, many buildings were completely destroyed, and falling obstacles killed many people.
• Second. As a part of Hiroshima explosion impact, many buildings were broken and destroyed, so that the city was wiped out. The average bomb may only partially the building and is not able to cause that serious destruction. The nuclear bomb, in its turn, makes extremely strong wave after the blast, and engulfs the large buildings, regardless of their size.
• Third. Hiroshima blast is not only one destructive wave. Technically, the explosion has got several phases. The first one lasts for quite a while, and creates that positive pressure, and later on follows a small amount of negative pressure. So, as the result, there occurs suction effect, which creates that impressive destructive force of the bomb, falling upside down.

Bomb Blast in Hiroshima and Nagasaki: environmental consequences

As a result of Hiroshima explosion, over 70% of buildings were burnt immediately, and in the area increased rates of cancer and certain other chronic diseases. Right after the explosion in the hypocenter, the temperature of the ground reached the mark of around 4.000 degrees Celsius (around 7.230 F). Right after Hiroshima nuclear blast, there followed acid rain, which was almost as dangerous as the radioactive air and ground in the area. Many volunteers, who entered the city to help the victims, died of radiation.

After the explosion, under the city appeared a mushroom-shaped cloud, which consisted of dangerous vapors, water, soil and certain other substances. Spread with the wind in the atmosphere, radioactive particles reached far from the hypocenter and polluted a vast territory around. Apart from the human losses, the nuclear bomb killed almost all forms of life in the area it reached. So, after the Hiroshima blast, everything within the radius of detonation (4.5 square miles) was decimated. The humans and animals, who survived after the explosion, had serious burns and were seriously injured with the flying glass. The trees were snapped off and uprooted in Nagasaki and nearby areas.

If compared with accidents on nuclear plants, which also cause serious damages to the environment, nuclear bomb explosions are far more dangerous. For instance, one single Hiroshima bomb blast was around 10 times more dangerous, than the accident on Chernobyl nuclear station, caused by an operator error in 1986.
Radiation in the area the bomb exploded in is way above the normal rates up to the present. And right after the accident it was extremely high, so thousands of survivors, who were not killed with the blast and did not die of burns, suffered cancer diseases and generic mutations, cause by the alterations in their DNA. Besides, nuclear impact negatively influenced the reproductive capacity.

From global point of view, Hiroshima blast, as well as any other nuclear accident, demolishes the ozone layer, and creates those holes. Later on, this all leads to global warmth, increase of the overall temperature and shortens the growing season. In future, such impact diminishes crops, which is a way to global starvation.

Life in Hiroshima during the World War II

During the World War II, Hiroshima was a serious headquarter for the Japanese imperial army, and here was located the Regional Army of Chugoku, as well as the Second General Army. Besides, the marine headquarters were located nearby, in the port of Ujina. This place was an important trading and shipping center, so in this area there was located a large amount of military supplies, so no wonder this strategic place was selected for the first nuclear attack of the Allies. As a result of numerous destructive bombings of Japanese cities, even the kids aged from 11 to 14 were mobilized, and worked on buildings demolishment and made firebreaks.

There were many speculations around the fact, that the city of Hiroshima did not experience those hard bombings, as Tokyo and 60 other Japanese towns and cities. There were many ides on that aspect:

• Some residents thought, that the U.S. saved this area to build occupational headquarters in some time;
• Some expressed the idea, that U.S. residents with Japanese background had petitioned the American government and managed to avoid bombing Hiroshima;
• There were more important military centers in the other cities, while only relatively small number of military personnel was headquartered in Hiroshima.

However, all of these rumors were completely ruined after the bombing. Hiroshima and Nagasaki summary shows, that both cities were completely destroyed, and the majority of citizens died or were seriously injured. And even years after the nuclear attack, Hiroshima and Nagasaki people have experienced serious health issues due to increased radiation rate in the area. So, no one of the theories, which were based on the assumption of the Allies mercy, was fair enough.

Hiroshima population in 1945

In the first years of war, population of Hiroshima with the number of citizens being around 381.000 was the peak index for the area. However, after 1942, many people were evacuated, since the area expected bombings from the Allies’ side. After several waves of systematic evacuation, which were ordered by the government, population in Hiroshima in 1945, right before the nuclear attack, equaled to 340.000. However the Japanese researchers note the Hiroshima population 1945 as close to 350.000 of citizens. Most probably, the true figure is somewhere in the middle.

Hiroshima population in the war years consisted of civilians and military. The main occupations of people here were also related with military actions. In this area there were located several aviation plants, which made boats, planes and parts for these means of transportation. Besides, there were manufacturing facilities, which were turned into the plants to assemble handguns and rifles. Civilians in this area, including children, manually made booby traps and gasoline bombs.

Hiroshima was an important communication center, and was important due to its geographical position, so that many military supplies were shipped and stored here. Besides, the city was an area, responsible for troops assembly and garrison was also located here. However, it is fair to say, that Hiroshima was a minor military center, however here were located around 40.000 of military personnel.

Influence of the nuclear bomb explosion to the health of Hiroshima citizens

After the bomb blast in Hiroshima, most people, who were close to the ground zero died immediately due to extremely high radiation doses. A number of people were killed with falling obstacles and glass. Out of 42.000-93.000 of deaths, which were reported by different sources as a result of dead bodies’ disposal, one third of the people, who got high radiation dosages, died on the fourth day. Many people also died due to serious burns.

Years after the explosion, people still had suffered different forms of radiation illness, since even with relatively low radiation dosages, the cells of the human body get influenced with the radiation, which results into cell deaths. Radiation blood injury is also a disease, which was caused by excessive dose of gamma rays, which was around 10.300 rads in Hiroshima.

Back in 1975, medical report studies in Hiroshima reported over 1.800 cases of leukemia. Cancer of the blood cells and overgrowth of white blood cells is also caused by the radiation influence. The other illnesses, caused by the ‘Little Boy’ explosion and the radiation, which followed, are:

• Cancers
• Chromosome changes
• Infantile deaths
• Bleeding tendency
• Inner mouth lesions

Structure and buildings of Hiroshima in World War II

One of the most meaningful buildings of the city, the Hiroshima Castle, became the base for the second general army headquarters. The city was protected by five batteries of anti-aircraft guns (2.8 and 3.1 inches caliber), since due to high military importance, it was assumed, that Hiroshima may be attacked by planes from air. Besides, here was located an anti-aircraft unit of the Japanese imperial army.

In the center of the city, apart from the lighter constructions, there were located certain reinforced buildings, which served as storages for food and military supplied. Outside of Hiroshima canter, there could be found many timber-made workshops, which were positioned right in between the Japanese houses. The industrial plants and facilities lay at the outskirts of Hiroshima. Due to the fact, that roofs of the civil buildings and even some industrial facilities were made of timber, the city could be easily destroyed with fire.

After the blast, the concrete buildings almost did not suffer, since their frames were built strong enough, in order to sustain earthquake danger, which is common for Japan. Due to downwards and sideways direction of the explosion wave, the Perfectural Industrial Promotion Hall managed to sustain, and is today a world heritage site of UNESCO.

The firebreaks were ineffective to stop the fire over the Japanese timber houses and buildings. Officially it was reported, that over 69% of the buildings in the city were completely wiped off by the blast, and the other 10% were seriously damaged. The nuclear bomb managed to burn off around 4.7 sq. mi of the ground in the city.

Nuclear blast. Hiroshima. Is there life after nuclear explosion?

Not many of us know, that right after the Hiroshima Nagasaki bomb blast in August, 1945, the city suffered another catastrophe. In September 1945, this city was stuck with a typhoon, which destroyed all the bridges in the area and killed around 3.000 of people. Nevertheless, the city was rebuilt, and now is a home to 1.154.400 of people. After the World War II, however, the population equaled to 137.197. In 2016, Barack Obama visited Hiroshima, and he was the first president to ever come here after the nuclear blast. Today, many people from different countries come to this city to get acquainted with its history and culture.