The designer, Mr. Jan Letzel a Czechoslovakian architect, used a brick construction partially reinforced with a steel frame with the exterior walls being made of stones and mortar. This was a modern building, the main body being three stories with a five-story stairwell capped with an oval shaped copper dome located in the center of the entrance hall. At that time such a grand European style building was extremely rare and the contrast of this modern beauty with the river surface led it to be counted as one of Hiroshima's major sites.

1945, August 6, 8:15 a.m. The first atomic bomb used in the history of mankind exploded approximately at a height of 580 meters, 160 meters southeast of the Hiroshima Prefectural Commercial Products Exhibition Hall. The force of this terrible blast was 35 tons per square meter with a blast speed of 440 meters. The atomic blast and heat wave washed over the Dome setting its roof ablaze and completely gutting the building. As the blast wave traveled in a nearly vertical direction while the center of the main building was miraculously spared from destruction, all the people within the building died instantly. The metal frame of the Dome, which was laid bare, formed the ruins that over time came to be called the "Atomic Dome" by the local residents.