1at 2: 45 on August 6th, 945, Colonel Tibbets of the U.S. Air Force took off from Tianning Island in the Mariana Islands with a B-29 heavy bomber "Ainola Guy" loaded with atomic bombs, and was escorted by two planes. It flies at an altitude of 9760 meters at a speed of 456 kilometers per hour. At 0800 hours, flying over Hiroshima, Japan, an atomic bomb weighing 9000 pounds, with a height of 10 feet and an equivalent of 20000 tons of TNT was dropped. At that time, Hiroshima had a population of 343,000. Ubin, which is closest to the south of Hiroshima, has long been used as an army shipping base, and there are many logistics factories and warehouses in the east of the city. Since April 1945, the 2nd General Command of the Japanese Army has been located here. At 8 o'clock in the morning, the atomic bomb exploded over the city center. Most residents near the explosion center were killed, but those who escaped groaned in burns. About 78,000 people died and 5 1000 people were injured or missing. There are more than 76,000 buildings in the city, of which 48,000 were completely destroyed and more than 22,000 were partially destroyed. The affected population reached1770,000.