At exactly fifteen minutes past eight in the morning, on August 6, 2015, a large bronze bell tolled 10 times. Its haunting tone echoed throughout a city that aside from the ever-present chirping of cicadas, fell dead silent.

The reality of what happened in this place on this date 70 years ago to the second was stark and inescapable to the 40,000 people gathered in central Hiroshima's Peace Park. While a boy in a white shirt and a young woman wearing a black dress struck the bell over the course of a minute on a blistering hot day, many in the crowd folded their handheld paper fans and bowed their heads. Some closed their eyes. Others interlaced their fingers in prayer.

As they do every August 6, Koko Kondo's thoughts not only drifted to the past, but also wandered into the future.

"I think every person who attended this ceremony is hoping for peace," she said moments after it ended. "We don't want a third, fourth, fifth bomb. Two is two too many."

Kondo, CAS/BA '69, is a hibakusha, the Japanese word for atomic bomb survivors. Their numbers are dwindling. For the first time their average age now tops 80, making them generations removed from the American, Japanese, and other Asian college students in the delegation AU history professor Peter Kuznick leads through Kyoto, Hiroshima, and Nagasaki every August.

No one has to say—it's widely understood that they're dying," says Sho Beppu, co-anchor of Newsroom Tokyo on NHK, Japan's public broadcasting network. He interviewed Kondo and Kuznick on a live television program on the sixth. "The anniversary is a big deal every year, but every 10 years it becomes a larger deal. There are, I think, special meanings for the 70th year. We know that on the 80th year, we will have much less people who will be able to speak and explain their experience."

Christopher Cayer, 32, will never forget his own. A PhD candidate in history at AU, he was a member of Kuznick's largest-ever group.

"It was surreal in the sense that the rigid formality was juxtaposed with that one moment of silence," he says. "Up until 8:15 it seemed like other ceremonies. Once they struck the bell and gave you that moment to reflect at the exact time that the bomb hit, that was a demarcation line for me. I couldn't get the image of human suffering out of my mind. I know that can be a little morbid, but I couldn't disassociate the impact of the weapon with the aftereffects of the violence."

That's exactly the type of visceral reaction that Kuznick, director of AU's Nuclear Studies Institute, hopes all the people he brings to Japan for an intense 10-day trip experience. An unabashed opponent of nuclear weapons and the United States' decision to use them, Kuznick first traveled to the country two decades ago. He met Kondo by chance outside a downtown Hiroshima department store, and she's been a member of the peace tour, as Kuznick calls his annual visit, ever since

"There's been a sharp reduction in nuclear arsenals since we started in 1995," he says. "However, there are still 16,300 nuclear weapons in the world. The United States and Russia have nuclear weapons pointed at each other on hair-trigger alert, which means they're ready to launch in 10 minutes. We now have nine nuclear states in the world. Forty countries have the capability of developing nuclear weapons. We have the risk of nuclear anarchy. It's more important than ever that we finally succeed in abolishing nuclear weapons."

In the heart of a city that was almost obliterated by a 9,700-pound uranium bomb that killed an estimated 70,000 people virtually instantaneously (90,000 to 140,000 are believed to have died from radiation poisoning by the end of 1945), Kuznick's words have particular resonance. He's fond of quoting the physicist I. I. Rabi, who said of the nuclear age, "Suddenly the day of judgment was the next day and has been ever since."

Seventy years ago, right here, where Kondo, Kuznick, Cayer, and thousands of others come from around the globe to mark one of mankind's grimmest anniversaries, the next day landed on Hiroshima, and a mushroom cloud sprouted above it.

The first dozen words of this story actually were written by Pulitzer Prize-winner John Hersey. They open his seminal book, Hiroshima, which humanized the victims to a Western audience in a way they hadn't been before. In 1999, a panel of reporters and academics convened by New York University named it the top work of twentieth-century American journalism.

Hersey's lead reads: "At exactly fifteen minutes past eight in the morning, on August 6, 1945, Japanese time, at the moment when the atomic bomb flashed above Hiroshima, Miss Toshiko Sasaki, a clerk in the personnel department of the East Asia Tin Works, had just sat down at her place in the plant office and was turning her head to speak to the girl at the next desk."

Originally filed as a magazine story to which the New Yorker devoted its entire August 31, 1946, issue, Hiroshima follows six survivors in the seconds, minutes, hours, days, and weeks after the bombing. One of them was the Reverend Kiyoshi Tanimoto, who then was the father of an eight-month-old daughter.

That daughter was Koko Kondo.

"I always wanted to know how I survived the atomic bomb, but I couldn't have asked my parents, because if I do, they have to recall the memory," she says. "My mother said she was unconscious, but then she heard some babies crying. Then she realized that inside of her arm was a baby—that was me."

Tanimoto, who earned a theology degree from Emory University in Atlanta, harbored no hatred toward America, which he visited often before and after the war. His daughter, however, was another story.

"As a little girl I don't know anything about war, but I thought the person who dropped the bomb on Hiroshima, they're the bad one, and I'm the good one," says Kondo, 70, who packs a huge personality into her tiny body. "Those pilots and the crew, I think someday I'm gonna grow up and find those guys and give them a punch or a kick."

At the age of 10, she had her shot. On a moment's notice Kondo's mother took her and her siblings to Los Angeles, where they were whisked to a television studio. Tanimoto, a Methodist minister who had gained a bit of notoriety from his role in the book, was to be featured on the television show This Is Your Life.

Standing in a corner next to the stage was a man young Koko had never seen before, yet one who had impacted her life profoundly.

"I asked my mother, 'Who is that guy?'" she recalls. "She said, 'He's Captain Robert Lewis.'"

Shocked that the copilot of the Enola Gay, the B-29 bomber that dropped the atomic bomb "Little Boy" on Hiroshima, stood just a few feet away, Koko plotted her revenge while the show's host, Ralph Edwards, asked Lewis how he had felt after releasing the bomb.

"He said, 'The city of Hiroshima disappeared.' Then he said, 'My god, what have we done?' I was just looking at his eyes; the tears just came out," says Kondo, her voice cracking 60 years later. "That's the moment I said, 'Gee, I don't know anything about this guy.' But until this moment, I thought he's the bad one, I'm the good one. While I was on the stage I look inside of my heart. Since I'm a PK—preacher's kid—I say, 'God, please forgive me. I don't know anything about this guy, but until this moment I hated him.'

"Then, I don't know why I did it, but I walk two or three steps, because I just wanted to touch his hand. So I did. He hold my hand very tightly. That's the moment I said, 'God, he's human being, not the monster, not the bad guy.' I'm so thankful that I met him. It taught me that when war starts, no one's going to be the winner. Everybody's going to hurt. If I hate, I should hate war itself, not this person."

The pro-peace message Kondo preached to the trip participants—most were students from AU and Japan's Ritsumeikan and Asia Pacific universities, but they also included a high school junior from Baltimore, a pastor and his 15-year-old son from New York, a Washington lawyer, and a Harlem social studies teacher—percolated through many of the other lectures delivered by professors and activists over the course of the week. Thirty-six hours before the anniversary, the group sat riveted as Setsuko Thurlow recounted in chilling detail how she narrowly escaped the bomb's wrath. Thirteen years old at the time, she was in an army building being trained to decode secret messages.

"On that very day, which happened to be Monday, at eight o'clock we were on the second floor of the wooden building about one mile away from the hypocenter [the point directly below the bomb's mid-air detonation]. The man in charge of the students was giving a pep talk. He said, go and show your patriotism to the emperor. At that moment I saw the blueish-white flash. I do remember the sensation of looking up in the air because of the strong blast generated by the explosion, all the buildings are being flattened. The building I was in was falling, and together with that, my body was falling. After that I lost my consciousness."

When Thurlow awoke, she was immersed in total darkness and silence.

"I knew I was faced with death, because I couldn't move my body. I never panicked, I was very serene. I heard the faint voices of the girls around me. 'Mother help me. God help me.' I can still hear those voices. Then I heard a very strong male voice: 'Don't give up. Keep pushing, keep kicking. I'm trying to free you.' He loosened me. I was able to crawl out. By the time I came out the [building] was on fire. That meant about 30 other girls who were with me in the same room were being burned alive. Two other girls managed to come up."

The city into which they emerged appeared post-apocalyptic. Dust and smoke obscured the blazing hot sun, which according to some estimates is cooler than the epicenter of the bomb blast. Fires raged everywhere. People staggered around holding fistfuls of their charred skin. The eyeballs of those unlucky souls who happened to be looking to the sky when the bomb detonated melted. More than 70 percent of the city's structures lay in ruin.

"After a while my eyes began to see some moving dark objects coming," Thurlow says. "They simply did not look like human beings. The funny thing I noticed was all the long hair women were wearing, they were rising straight up. They were burned, bleeding,and sweating. Nobody was shouting or yelling. If they said anything they just whispered, 'Please give me water.'

"I felt my job is to tell the world what nuclear weapons did, so that we can be smart enough not to let that happen again."

But knowing that its enemy was severely staggered, did the United States have to use atomic bombs to end the war, or was it seeking to assert its geopolitical and military dominance to the world?

Interestingly, the Americans and Japanese on the trip each tended to point more to their own government's missteps and failings when wrestling with the victim versus victimizer question.

"The myth that American students learn throughout their youth is that the atomic bomb ended the war in the Pacific," Kuznick says. His positions—that the United States was morally wrong to have dropped the bomb, and that President Harry Truman, who ultimately made the decision to do it, was a war criminal for using a weapon that indiscriminately targeted civilians—are laid out in unapologetic and unambiguous terms in the Untold History of the United States, a New York Times bestselling book and 10-part Showtime documentary series he coauthored with Academy Award-winning filmmaker Oliver Stone (who joined Kuznick's peace tour in 2013).

"The reality is that the Americans knew there were two ways to end the war without the atomic bomb. Number one, change the surrender terms to let the Japanese know they could keep the emperor, and number two, wait for the Soviet invasion in early August and let that end the war, as American intelligence repeatedly said it would. The question that historians debate is why did the United States drop the bomb if the Japanese were about to surrender anyway and we knew they were about to surrender. Truman himself refers to an intercepted July 18 cable as 'the telegram from the Jap emperor asking for peace.' What we're arguing is that the United States wanted to drop the bombs, and that the real target was not the Japanese, the real target was the Soviet Union, which is exactly how the Soviet Union interpreted it."

Yuki Tanaka is a Japanese professor who's taught in Australia for many years (his accent has to be one of a kind). Author of Hidden Horrors: Japanese War Crimes in World War II, he argues that Japan was hardly blameless in inciting America's actions. In disturbing detail he described Japanese wartime atrocities including cannibalism; the slaughter and starvation of prisoners of war; the rape, enforced prostitution, and murder of noncombatants; and biological warfare experiments. Tanaka also once headed a Hiroshima People's Tribunal that condemned Truman and other American leaders as war criminals.

"The Battle of Okinawa finished at the end of June [1945], and [Japanese Emperor Hirohito] still didn't want to surrender," he told the group. "In my words, he was also morally responsible for the bombing of Hiroshima and Nagasaki. Because we don't seriously discuss the crimes we committed against the Asians, we never discuss the conduct of US forces. We've been doing this vicious circle for the last 70 years."

In fact, Japan's viewpoints on the war are so varied and complex there's not even a consensus among its people on what to call it. What most of us know as World War II also is referred to by the Japanese as the Fifteen-Year War or the Asia Pacific War.

Moeka Sakata views these questions through a unique lens. A Japanese who's studying at AU, she grew up in the town of Fukuoka (about a 90-minute flight from Tokyo) but attended high school in Colorado for a year.

"Japanese people talk about the atomic bomb a lot, but in the US everything is more about Pearl Harbor," she says. "Everyone feels like a victim."

Reading about atomic weapons or studying them in a classroom in Dallas or Dublin or Delhi can make it easy to forget that regardless of who's ultimately to blame, their use had devastating consequences for the hundreds of thousands of men, women, and children in Hiroshima that morning—many of whom, like victims of war throughout time, were innocents simply trying to make it through another day.

In 1945 Hiroshima was a port and industrial city with a population of about 300,000 civilians, 50,000 troops, and 55,000 Korean slave laborers. Despite being home to a major military headquarters, it had been spared conventional bombing in part to allow for an easier and more accurate assessment of the atomic bomb's capabilities. US officials ultimately chose it over Kokura, Nagasaki, and Niigata.When "Little Boy" was dropped its specific target was the Aioi Bridge, but due to a crosswind it detonated directly over Shima Surgical Clinic in the middle of town.

"People were eating breakfast, people were going to work, people were making love," says Kuznick, who's leading his students on a walking tour through downtown Hiroshima. He's standing next to a small plaque that marks the hypocenter on a nondescript side street a few blocks from the Peace Park.

This is not an inconspicuous group. A documentary film crew and several members of the Japanese media trail Kuznick, who's a minor celebrity here. After he speaks a Japanese woman recognizes him and asks for a photo. He obliges.

In the summer Kuznick helped bring an exhibit of artifacts collected after the atomic bombings and six large painted folding screens depicting them to the American University Museum at the Katzen Arts Center. Masato Tainaka, a reporter for the Asahi Shimbun newspaper, traveled to Washington to interview Kuznick about the exhibit and the atomic bombings themselves. The resulting story, he says, garnered much interest from the Japanese public.

"We need to give our readers different points of view, and Peter was a driving force for me to convey the message," Tainaka says.

After the war Hiroshima was reborn as a city dedicated to peace and the abolition of nuclear weapons. Today it's a thoroughly modern metropolis that features state-of-the-art transportation systems; scores of brand-name stores including Gucci, Cartier, and Chanel; fast-food staples like McDonald's and 7-Eleven seemingly everywhere; and a major Mazda factory (the city's Carp baseball team plays in Mazda Zoom-Zoom Stadium). It's also home to the Hiroshima Peace Culture Foundation and the Hiroshima Peace Memorial Museum. During the August 6 ceremony, its mayor reads a peace declaration.

"As long as nuclear weapons exist, anyone could become a hibakusha at any time," Mayor Kazumi Matsui said. "If that happens, the damage will reach indiscriminately beyond national borders. People of the world, please listen carefully to the words of the hibakushaand, profoundly accepting the spirit of Hiroshima, contemplate the nuclear problem as your own."

The Peace Park occupies about 30 acres that once comprised the city's busiest downtown commercial and residential district. Its centerpiece is the former Hiroshima Prefectural Industrial Promotion Hall, the closest building to the hypocenter that wasn't flattened. The so-called A-Bomb Dome, which was severely damaged, is the only structure in the area that the city didn't level or repair. A plaque outside it reads, in part, "As a historical witness that conveys the tragedy of suffering the first atomic bomb in human history and as a symbol that vows to faithfully seek the abolition of nuclear weapons and everlasting world peace.

This message of forward-looking hope, rather than backward-looking blame, is typical of language and attitude throughout Hiroshima. There are few hints of anti-Americanism (to the ire of some). Even the inscription on the memorial cenotaph in the center of the park is a simple phrase generally translated as, "We shall not repeat the error."

As the tour continues, Kuznick and Kondo point out heart-wrenching sites, including a mound where the unidentified remains of thousands of victims were buried, jutting like a grassy tombstone. Nearby, a monument is dedicated to the approximately 20,000 Koreans killed by the bomb.

But there also are uplifting stops. The Children's Peace Monument is a bronze likeness of a girl with outstretched arms and a folded paper crane rising above her. It's based on the true story of Sadako Sasaki, who was two years old at the bombing and died of leukemia a decade later. She believed that if she folded 1,000 paper cranes she would be cured. Built with contributions from more than 3,200 schools in Japan and nine countries, the monument was unveiled in 1958. To this day, visitors fold cranes and place them near the statue.

The bell that's a part of Sadako's Statue, as it's known, was a popular gathering spot on the evening of the anniversary; in contrast to the morning's somber tone, a feeling of optimism and hope filtered throughout the park as kids continually rang it. A group of Japanese girls held signs offering hugs for peace. Thousands from all over the world had returned to participate in a Toro nagashi, an informal ceremony in which thousands of lanterns carry messages of peace to the spirits of victims. The mood was festive.

As the line to light and release the green, red, blue, and yellow paper lanterns snaked through the park, Sakata, SIS/BA '16, and Reina Shiotari, a Japanese student from Osaka, contemplated their words.

"We have to make an effort to reflect on what each of us—American and Japanese—did, and then we're going to have to reconcile," Sakata wrote in Japanese on the lantern. "Please bring peace and joy to people who died from the atomic bomb and also the survivors who still suffer psychologically and physically. Peace to the world."

Shiotari's eyes began to water as she recounted what she had written using the same Sharpie, on the same lantern, also in Japanese.

"Seventy years ago, on August 6, not only a lot of people lost their lives, but also their dreams and their hopes disappeared. I think we have to keep on working to bring on peace. We also have to study what Japanese people did to other Asian people. I am going to swear that I keep [working] for peace."

When they reached the front of the line they carefully climbed down to the bank of the Motoyasu River, bowed their heads and set their lantern afloat toward the A-Bomb Dome, where it joined hundreds of others illuminating the night in a brilliant rainbow of light.