At 2:45 in the morning of August 6, 1945, an American B-29 bomber flew north from Tinian Island in the Marianas toward Japan. Three and a half hours later, over the city of Hiroshima, the Enola Gay dropped an 8,900-pound atomic weapon from its specially modified bomb bay. Two thousand feet above the ground, the bomb, dubbed "Little Boy" by its makers, detonated, leveling almost 90% of the city. On August 9, another B-29, Bockscar, set out for the Kokura Arsenal on the southwest Japanese island of Kyushu. Foul weather, however, persuaded the pilot to proceed instead toward Nagasaki, the home of a Mitsubishi torpedo factory. Over this secondary target Bockscar dropped a larger device, code-named "Fat Man." Local geography spared Nagasaki from the near total devastation suffered by Hiroshima; only one third of the city was destroyed. Altogether, the two bombings killed an estimated 110,000 Japanese citizens and injured another 130,000. By 1950, another 230,000 Japanese had died from injuries or radiation. Though the two cities were nominally military targets, the overwhelming majority of the casualties were civilian
Dropping the First Atomic Bomb At 2:45 A.M. local time, the Enola Gay, a B-29 bomber loaded with an atomic bomb, took off from the US air base on Tinian Island in the western Pacific. Six and a half hours later, at 8:15 A.M. Japan time, the bomb was dropped and it exploded a minute later at an estimated altitude of 580 + 20 meters over central Hiroshima. The Hiroshima Bomb Size: length - 3 meters, diameter - 0.7 meters. Weight: 4 tons. Nuclear material: Uranium 235. Energy released: equivalent to 12.5 kilotons of TNT. Code name: "Little Boy".
Maximum temperature at burst point: several million degrees centigrade. A fireball of 15-meters radius formed in 0.1 millisecond, with a temperature of 300,000 degrees centigrade, and expanded to its huge maximum size in one second. The top of the atomic cloud reached an altitude of 17,000 meters. Black Rain Radioactive debris was deposited by "black rain" that fell heavily for over an hour over a wide area. Demaging Effects of the Atomic Bomb Thermal Hear. Intense thermal heat emitted by the fireball caused severe burns and loss of eyesight. Thermal burns of bare skin occurred as far as 3.5 kilometers from ground zero (directly below the burst point). Most people exposed to thermal rays within 1-kilometer radius of ground zero died. Tile and glass melted; all combustible materials were consumed.
Bodily Injuries Acute symptoms. Symptoms appearing in the first fourmonths were called acute. Besides burns and wounds, they included: general malaise, fatigue, headaches, loss of appetite, nausea, vomiting, diarrhea, fever, abnormally low white blood cell count, bloody discharge, anemia, loss of hair. Aftereffects. Prolonged injuries were associated with aftereffects. The most serious in this category were: keloids (massive scar tissue on burned areas), cataracts, leukemia and other cancers.