Damage from the Atomic Bombing

B-5 Damage Caused by the Heat Rays

 “Verification of the Heat Rays”, “Material Damage Caused by the Heat Rays”, “Damage caused by the Fires”, and “Human Injuries Caused by the Heat Rays” are explained with artifacts and photographs.



    Verification of the Heat Rays

A large number of heat rays, released from the fireball which appeared from the explosion, wrapped the surface of the earth with abnormally high temperatures in as little as 3 seconds from the explosion. The temperature of the earth’s surface was estimated to reach 3,000 degrees to 4,000 degrees centigrade at the hypocenter, 1,800 degrees at a distance of 1 kilometer, and more than 600 degrees in the vicinity of 1.5 kilometers away from the hypocenter. The heat caused a large-scale fire. Although the distance reached by the heat rays vary due to the topography of the Urakami district, people 4 kilometers away from the hypocenter outside the structures and air-raid shelters suffered severe burns.


Material Damage Caused by the Heat Rays

All flammable objects near the hypocenter burst into flames due to the intense energy of the heat rays. The fierceness of the heat rays can be seen in the melted glass, boiled and bubbled tiles, and the burnt and blackened stones. Even though the strength of the heat rays weakened with the distance from the hypocenter, the surfaces of clothes, power poles, and trees within 2 kilometers were burned or charred.


Damage Caused by the Fires

Damage from the heat rays and the blasts were increased further by the subsequent fires. Although the blast only partially destroyed many houses, they ended up being completely burned by the fires afterwards. The number of completely burned or destroyed houses amounted to 12,900 and the number of partially destroyed or burned houses amounted to 5,509. Fires also increased the number of victims. There were many people who were trapped under collapsed houses who would have been saved with just external wounds if the fire had not reached them.


Human Injuries Caused by the Heat Rays

The few seconds of high temperature from the heat rays burned the skins of people. The fierceness of the heat rays caused injuries that are beyond those of regular burns. The degree of the burns differed with the distance from the hypocenter, but particularly in severe cases, the burned skin became tattered, and peeled off by itself revealing the subcutaneous tissues and bones. The heat rays alone were fatal within 1.2 kilometers, and the bodies of people around the vicinity of the hypocenter were instantly turned to ash by the high temperatures; It is said that       even the fluids inside people’s organs evaporated.