FILE - In this Aug. 6, 1945, file photo, the "Enola Gay" Boeing B-29 Superfortress lands at Tinian, Northern Mariana Islands, after the U.S. a…
A. At 8:15 a.m., the U.S. B-29 bomber Enola Gay dropped a 4-ton "Little Boy" uranium bomb from a height of 9,600 meters (31,500 feet) on the city center, targeting the Aioi Bridge. The bomb exploded 43 seconds later, 600 meters (2,000 feet) above the ground. Seconds after the detonation, the estimated temperature was 3,000-4,000 degrees Celsius (5,400-7,200 degrees Fahrenheit) at ground zero. Almost everything within 2 kilometers (1.2 miles) of ground zero was destroyed by the blast and heat rays. Within one hour, a "black rain" of highly radioactive particles started falling on the city, causing additional radiation exposure.
