Peace Statue in Nagasaki's Peace ParkKyodo / Reuters

In a somber acknowledgment of the impact of nuclear weapons, President Obama on Friday visited Hiroshima, where 120,000 Japanese, most of them civilians, were killed when the United States dropped an atomic bomb on the city on August 6, 1945.

Obama is the first sitting U.S. president to visit the city. While he did not expressly apologize for the bombing, he did honor the dead and looked toward a future without weapons of mass destruction.

“That is the future we can choose,” he said after laying a wreath at Peace Memorial Park. “A future in which Hiroshima and Nagasaki are known not as the dawn of atomic warfare but as the start of our own moral awakening.”

It was a touching tribute to Hiroshima, and a rare mention of the other city on which the U.S. dropped an atomic bomb. The two cities have been coupled for the impact of the events that ultimately led to Japan’s surrender in World War II. But Nagasaki’s story is often untold.

Three days after the U.S. dropped an atomic bomb on Hiroshima, it set its eyes on Nagasaki. On August 9, the U.S. dropped an atomic bomb on the city of 263,000. The blast created 624 mile-per-hour winds and 7,050 degrees of heat. The bomb was more powerful than the one dropped on Hiroshima, but the hills of the city blocked some of the damage. Still, 75,000 people ultimately died from the explosion. Only 150 of those deaths were soldiers.

William L. Laurence, The New York Times reporter who served as an eyewitness to the bombing, said Nagasaki was chosen that night because the aircrafts circled other potential targets but “found no opening in the thick umbrella of clouds that covered them. Destiny chose Nagasaki as the ultimate target.”

We flew southward down the channel and at 11:33 crossed the coastline and headed straight for Nagasaki about a hundred miles to the west. Here again we circled until we found an opening in the clouds. It was 12:01 and the goal of our mission had arrived.

We heard the pre-arranged signal on our radio, put on our ARC welder's glasses and watched tensely the maneuverings of the strike ship about half a mile in front of us.

"There she goes!" someone said. Out of the belly of the Artiste what looked like a black object came downward.

Captain Bock swung around to get out of range, but even though we were turning away in the opposite direction, and despite the fact that it was broad daylight in our cabin, all of us became aware of a giant flash that broke through the dark barrier of our ARC welder's lenses and flooded our cabin with an intense light.

We removed our glasses after the first flash but the light still lingered on, a bluish-green light that illuminated the entire sky all around. A tremendous blast wave struck our ship and made it tremble from nose to tail. This was followed by four more blasts in rapid succession, each resounding like the boom of cannon fire hitting our plane from all directions.

Observers in the tail of our ship saw a giant ball of fire rise as though from the bowels of the earth, belching forth enormous white smoke rings. Next they saw a giant pillar of purple fire, 10,000 feet high, shooting skyward with enormous speed.

By the time our ship had made another turn in the direction of the atomic explosion the pillar of purple fire had reached the level of our altitude. Only about 45 seconds had passed. Awe-struck, we watched it shoot upward like a meteor coming from the earth instead of from outer space, becoming ever more alive as it climbed skyward through the white clouds. It was no longer smoke, or dust, or even a cloud of fire. It was a living thing, a new species of being, born right before our incredulous eyes.

At one stage of its evolution, covering missions of years in terms of seconds, the entity assumed the form of a giant square totem pole, with its base about three miles long, tapering off to about a mile at the top. Its bottom was brown, its center was amber, its top white. But it was a living totem pole, carved with many grotesque masks grimacing at the earth.

Then, just when it appeared as though the thing has settled down into a state of permanence, there came shooting out of the top a giant mushroom that increased the height of the pillar to a total of 45,000 feet. The mushroom top was even more alive than the pillar, seething and boiling in a white fury of creamy foam, sizzling upwards and then descending earthward, a thousand old faithful geysers rolled into one.

It kept struggling in an elemental fury, like a creature in the act of breaking the bonds that held it down. In a few seconds it had freed itself from its gigantic stem and floated upward with tremendous speed, its momentum carrying into the stratosphere to a height of about 60,000 feet.

But no sooner did this happen when another mushroom, smaller in size than the first one, began emerging out of the pillar. It was as though the decapitated monster was growing a new head.

As the first mushroom floated off into the blue it changed its shape into a flower-like form, its giant petal curving downward, creamy white outside, rose-colored inside. It still retained that shape when we last gazed at it from a distance of about 200 miles.

Six days later, Japan surrendered.

The impact of the second atomic bomb is the subject of historical debate. In the aftermath of the war, the U.S. argued it was instrumental and necessary in encouraging Japan’s surrender. Others disagree, though.

Susan Southard, in a 2015 column for The New York Times, argues the narrative that the atomic bomb dropped on Nagasaki brought about the end of the war is a false one. She writes:

But it is now well known that the surrender was prompted at least as much by the Soviet Union’s decision to join the Allies in the war against Japan. Just 11 hours before the Nagasaki bombing, 1.5 million Soviet troops crossed into the Japanese puppet state in Manchuria, in northern China, and attacked the depleted Japanese Army there on three fronts.

The United States expected the Soviet action, but the delivery of the second atomic bomb was not dependent on the timing of the Soviet invasion, Tokyo’s response, or even a specific order from President Harry S. Truman. His sole directive had been to use nuclear weapons on Japan “as made ready” — and on Aug. 8, the second bomb’s assembly was complete.

The next morning — 30 minutes before the Nagasaki bombing — Japan’s Supreme War Council convened to try yet again to find agreement on surrender terms. Stalin’s declaration of war had ended any last hope of Soviet help in attaining more favorable surrender terms.

Council members pressing for immediate surrender were gravely concerned about lack of food and supplies for Japanese troops, the dire domestic situation and the Hiroshima bombing. Militarists were willing to fight to the death for the guaranteed preservation of Emperor Hirohito’s postwar sovereignty. When news of the Nagasaki attack arrived, the deliberations continued without further mention of it. That night, Hirohito broke the deadlock and sanctioned surrender.

Southard says the bombing of Nagasaki was ignored in the U.S. almost immediately. Both it and Hiroshima, though, shared the devastating effects of an atomic bomb—massive loss of life, radiation poisoning, and years of ailments.

Japanese Emperor Hirohito even said the prospect of further atomic bomb attacks from the U.S. was daunting.

“Moreover, the enemy now possesses a new and terrible weapon with the power to destroy many innocent lives and do incalculable damage,” he said in his declaration of surrender. “Should we continue to fight, not only would it result in an ultimate collapse and obliteration of the Japanese nation, but also it would lead to the total extinction of human civilization.”

Ultimately, Obama decided to only visit Hiroshima. While Nagasaki received passing mentions from the White House in the run-up to Obama’s visit to Japan, survivors of the second atomic bomb viewed his visit to Hiroshima as meaningful enough. Some hibakusha, or survivors, told the Times the most important thing was for the president to hear their stories.

But some officials did ask the president to visit Nagasaki. In April, Tomihisa Taue, the city’s mayor, handed a letter to Caroline Kennedy, the U.S. ambassador to Japan, urging the president to visit. The letter, in part, read:

“Please express your country’s steadfast determination to achieve the abolition of nuclear weapons through a message, stating that Nagasaki must be the last place to suffer the devastation they bring. The people of Nagasaki ardently wish to see the realization of both your visit to Hiroshima, and of course to Nagasaki.”

Taue made a similar request before Obama’s 2009 trip to Japan.

While Obama did not visit Nagasaki, he, like many have over the past 71 years, paired that city with Hiroshima to talk about the ultimate impact of nuclear weapons. Indeed, in a speech during that 2009 visit, he said, “The memories of Hiroshima and Nagasaki are etched in the minds of the world.”

We want to hear what you think about this article. Submit a letter to the editor or write to letters@theatlantic.com.