A mother and her daughter pray for the atomic bomb victims in front of the cenotaph for the victims of the 1945 atomic bombing, at Peace Memorial Park in Hiroshima, western Japan, August 6, 2015, on the 70th anniversary of the world's first atomic bombing of the city. Japan on Thursday marks the 70th anniversary of the attack on Hiroshima, where the U.S. dropped an atomic bomb on August 6, 1945, killing about 140,000 by the end of the year in a city of 350,000 residents. It was the world's first nuclear attack. The Atomic Bomb Dome, or Genbaku Dome, was the only structure left standing in this district of the city and has been preserved as a peace memorial. REUTERS/Toru Hanai