Hiroshima is holding a memorial to mark the 65th anniversary of the world's first atomic bomb attack, with the U.S. and other major nuclear powers attending for the first time. This year's memorial, which began with the offering of water to the dead, is being attended by representatives of the U.S., Britain, France and U.N. Secretary-General Ban Ki-moon. Altogether, 75 countries are represented. About 140,000 people were killed or died within months when the American B-29 "Enola Gay" bombed Hiroshima on Aug. 6, 1945. Three days later, about 80,000 people died after the United States attacked Nagasaki.