Rubble believed to be from the Hiroshima Peace Memorial, also known as the Atomic Bomb Dome, was salvaged Wednesday from the nearby Motoyasu River by a crane with support from Hiroshima University.
Rebun Kayo, a 35-year-old graduate student at Hiroshima University, discovered granite chunks last June that had apparently been part of the building, which is a World Heritage site.
Two pieces of granite were recovered from the river that runs in front of the dome. The larger piece measures 110 by 55 cm and weighs close to 300 kg, according to Kayo.
The stone is thought to have been used for the eaves on the building's third floor.
The dome was the only structure left standing in the area of the blast on Aug. 6, 1945.
Many victims of the U.S. atomic bombing died in the Motoyasu River after searching for water to quench their thirst caused by the blast.
"I found these stone pieces, feeling as if I were gathering ashes of those who perished," Kayo said.
