In Japan, many of the survivors and their families, along with thousands of others have gathered at Peace Memorial Park - the epicenter of the attack. Hiroshima's mayor and Japan's prime minister also attended the ceremony and spoke of a world without nuclear weapons.
Three days after the Hiroshima attack, the U.S. dropped another bomb on Nagasaki, bringing Japan to surrender.
Copyright 2015 Nexstar Broadcasting, Inc. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.