Whether the decision to use atomic weapons against Japan was right or wrong, 65 years later the Hiroshima Peace Memorial Ceremony remains as emotionally charged as ever -- and a United States representative attended for the first time.
A peace toll sounded today to mark the minute the first atomic bomb was unleashed on humankind; on Hiroshima at 8:15 a.m. Aug. 6, 1945. The United States dropped a second bomb on Nagasaki three days later.
"No one else should have to suffer this horror," said Hiroshima Mayor Tadatoshi Akiba, whose speech ended with the release of hundreds of doves to symbolize peace.
About 140,000 people died in Hiroshima then. Few survived. Fewer live to willingly share their stories.
For decades after the end of Word War II, many Japanese hid that they were survivors, given the stigma of being exposed to radiation.
While the number of atomic bomb survivors, or "hibakusha" in Japanese, is dwindling, their voices are growing stronger.
At an average age of 76 years, survivors speak out for recognition of their ailments and seek medical aid from the government.
"For those waiting to be recognized as sufferers of atomic bomb diseases," Japanese prime minister Naoto Kan said during his speech, "the government will do its best to grant recognition at the earliest date possible. Furthermore, we will advance deliberations on revising the system for the recognition of atomic bomb diseases through changes to the law."
Survivors also offer an oral history for future generations.
"It was a burnt black piece of mass dripping with bodily fluids," survivor Mikiso Iwasa told ABC News. "My mother was killed as a thing. Not as a human."
They openly shared vivid images forever seared into their hearts and minds.
"I was 7 years old when I was nuked," Michiko Kodama told ABC News. "People whose eyeballs had popped out of their sockets and were dangling in front of their faces."
Today in Hiroshima, their voices were heard by representatives spanning 74 countries.
The United Nations Secretary General attended the ceremony for the first time. Ban Ki-moon met with survivors afterwards.
This was the first attendance for official representatives from the United States, Britain and France, drawn by the big anniversary and an opportunity to push nuclear disarmament.
"For the sake of future generations," U.S. Ambassador to Japan John Roos said in a statement, "we must continue to work together to realize a world without nuclear weapons."
Some people believe Washington's decision to send an ambassador to the ceremony could open the door to a future visit to Hiroshima by President Obama, which would be unprecedented for a sitting president. He has been to Japan.
Where's President Obama?
"If Obama is so keen about abolishing nuclear weapons," an attendee said to Japanese broadcaster NHK, "then he should visit Hiroshima."
The end hope here is to prevent the use of atomic weapons in today's radically different world.
Diana Alvear contributed to this report.