The original Motoyasu Bridge was built by Terumoto Mori when he built Hiroshima Castle and constructed the castle town 400 years ago. The bridge exposed to the atomic bombing was built in 1926. With spherical ornamental lights topping the main columns on both riverbanks and light posts lining the bridge itself, it was quite modern and stylish for its day. However, when the metal in the lighting fixtures was requisitioned for the war effort, lights were installed instead in stone lanterns.
The girders withstood the atomic bombing, but the blast pushed the coping stones on the main columns outward and knocked the railings off both sides into the river. From this evidence, people thought that the hypocenter was located on a line extended from the bridge.
The surviving bridge was used for another 40 years after the bombing, but it eventually deteriorated. Construction of a new bridge began in 1989 and was completed in 1992.
The new bridge was designed to resemble the original one. It incorporated four main columns and two pillars from the A-bombed bridge into its design. Two pillars from the old bridge lying to the east of Motoyasu Bridge serve as a historic monument.