Photos: Japan Commemorates 70th Anniversary of Hiroshima Bombing

The U.S. dropped an atomic bomb on the Japanese city of Hiroshima 70 years ago Thursday in the hopes it would bring a rapid end to World War II.

Approximately 70,000 people died instantly when the uranium bomb, dropped by the American B-29 bomber Enola Gay, exploded 2,000 feet above the city. Nicknamed "Little Boy," the bomb had the explosive force of 12,000 and 15,000 tons of TNT.

Three days after the bombing of Hiroshima, which occurred at around 8:10 a.m. local time on August 6, 1945, a second bomb was dropped on Nagasaki, 260 miles away. An estimated 210,000 people died as a result of both bombings.

"It is an atomic bomb. It is a harnessing of the basic power of the universe," then-President Harry S. Truman said in a statement released 16 hours after the bomb was dropped. "The force from which the sun draws its power has been loosed against those who brought war to the Far East." Newsweek described the bombing as a "fabulous stride in war and science" in an article published after the bombing.

World War II would officially end in Asia on September 2, 1945, about four months after ending in Europe. Injuries from the bombing lasted weeks, months and years later, including burns, cancers and birth defects in children.

A bell tolled in Hiroshima at 8:15 a.m. on Thursday and Japan observed at minute's silence to mark the bombing's 70th anniversary. Japanese Prime Minister Shinzo Abe spoke at a commemoration ceremony in Hiroshima, where he told 40,000 people that the city had been "revived" to become a "city of culture of prosperity." Foreign delegates, including U.S. Ambassador to Japan, Caroline Kennedy, were also in attendance.

"To coexist, we must abolish the absolute evil and ultimate inhumanity that are nuclear weapons. Now is the time to start taking action," said Abe.