Hiroshima: Before And After

A Picture of the Hiroshima Peace Memorial (Below), the closest building to the blast that survived. Sourced at http://upload.wikimedia.org/wikipedia/commons/5/51/A-Bomb_Dome.jpg

Before The Bombing

Hiroshima, during WWII, was a fairly significant city for industry and military involving Japan. Many military camps were located nearby, including the HQ of the Fifth Division and Field Marshal Shunroku Hata's 2nd General HQ, which commanded the defense of all of southern Japan. The city had purposely been left untouched by bombers to measure out the damage of the blast when the city was in a pristine condition. Another reason why Hiroshima was targeted for bombing was that it had no POW camps, eliminating the risk of killing our captured troops.

After!!!

Picture sourced at http://en.wikipedia.org/wiki/Image:Hiroshima_aftermath.jpg 

The release at 08:15 (Hiroshima time) was uneventful, and the gravity bomb known as "Little Boy", a gun type fission weapon with 130 pounds of uranium-235, took 57 seconds to fall from the aircraft to the predetermined detonation height about 1,900 feet above the city. It created a blast equivalent to about 13,000 tons of TNT. The U-235 weapon was considered very inefficient, with only 1.38% of its material fissioning. The radius of total destruction was about 1 mile, with resulting fires across 4.4 square miles. Infrastructure damage was estimated at 90 percent of Hiroshima's buildings being either damaged or completely destroyed. Although the blast was insignificant compared to "Fat Man", its plutonium based brother, the resulsts were still devastating.