On Monday, August 6, 1945, the Little Boy nuclear weapon was released on Hiroshima. Some military camps were in the vicinity, including the headquarters of the Fifth Division and those of the Second General Army of Field Marshal Hata Shunroku, who commanded the defense of the entire southern part of the country.
The Little Boy bomb was dropped at 08:15 a.m. and reached 55 seconds the height determined for its explosion, approximately 600 meters above the city. It is estimated that instantaneously the temperature rose to more than one million degrees Celsius, which burned the surrounding air, creating a ball of fire of 256 meters in diameter. In less than a second the ball expanded to 274 meters, the radius of total destruction was 1.6 kilometers, causing fires in 11.4 km².
Between 70,000 and 80,000 people, about 30% of the population of Hiroshima, died instantly, while another 70,000 were injured.
original post published by DENIX on their website