On August 6, 1945, Lt. Col. Paul W. Tibbets’ B-29 Enola Gay bomber took off to the targeted areas preceded by three weather reconnaissance planes. Six to seven kilometers behind the bomber was another plane used to record the parameters of the nuclear explosion, and 70 kilometers behind trailed another bomber to photograph the results of the explosion. One hour before the bombing, Japanese early-warning radar showed the approach of several aircraft but due to the insignificant number of planes the air raid warning in Hiroshima was soon called off.

At 8:15 a.m., after visual sighting, the Little Boy atomic bomb was dropped on Hiroshima from an altitude of 10,000 meters. The bomb contained a uranium charge equivalent to about 20,000 metric tons of trinitrotoluol. The bomb exploded at an altitude of 600 meters.

As a result, about 80,000 people died instantly, over 12,000 were missing, and another 40,000 were injured. Fires ravaged for hours within four kilometers from the epicenter of the blast. Buildings were completely destroyed in an area of 12 square kilometers, 62,000 of the 90,000 houses were leveled.

On August 9, 1945, at 11:01 a.m., a bomber dropped the Fat Man atomic bomb with a plutonium charge equal to 20,000 metric tons of TNT on the city of Nagasaki. The irregular terrain and missing the target (the center of the city) by two kilometers somewhat reduced the number of casualties and the amount destruction. Over 73,000 people were killed or missing with 35,000 more dying later of radiation and wounds. More than 50 percent of the victims suffered burns, up to 30 percent were injured by the atomic blast wave, 20 percent suffered from radiation. Subsequent fires destroyed most of the buildings.

The two blasts accounted for about 300,000 victims (dead or missing), while approximately 200,000 people suffered from radiation burns or poisoning.

The first World Conference against Atomic and Hydrogen Bombs met in Hiroshima on August 6, 1955. In 1985, the Treaty of Rarotonga declared the South Pacific a nuclear free zone.

Hiroshima symbolizes the mass destruction weapons ban cause. The whole world marks Hiroshima Day, and memorial ceremonies are held in the city on August 6. An empty space with ruins is left in the city center forever as reminder of the appalling tragedy.

The Peace Pilgrimage for a nuclear free future is held in Japan every year covering more than 10,000 kilometers along 13 routes connecting all 47 prefectures. The walkers gather on August 6 at the Hiroshima Peace Memorial Park, which surrounds the blast epicenter.

The Memorial Cenotaph, under its concrete canopy, holds the names of the blast victims under a limestone slab. The names of recently deceased survivors are added to the list every year. The slab is inscribed: “Let all the souls here rest in peace for we shall not repeat the evil.”

The Peace Memorial Museum is nearby.

One of the three Peace Bells in the Peace Park close to the museum is inscribed, and visitors are encouraged to ring it for world peace. Another, with a heart-rending mournful sound, is rung only once a year for the Peace Memorial Ceremony, with its one minute of silence.

The 2010 Memorial Ceremony was the first to be attended by a US representative. That was John Roos, the US Ambassador to Japan.

UN Secretary General Ban Ki-moon also participated in the ceremony.

Nobel Peace Prize winners Frederik Willem de Klerk, Mairead Corrigan Maguire, Mohamed ElBaradei, Jody Williams, Shirin Ebadi and Tenzin Gyatso, the 14th Dalai Lama, visited the Peace Memorial the same year.

In 2011, nuclear energy safety and renewable energy sources were discussed during the Memorial Ceremony, which commemorated the 66th anniversary of the tragedy.

The 2012 ceremony was attended by Clifton Truman Daniel, the oldest grandson of President Harry Truman.