Kunihiko Iida was only three when the world around him suddenly went black.
Trapped under the rubble of his grandpa's house after the world's first nuclear attack, the young boy tried to scream for help.
"I tried to call out to my mother 'help me', but I couldn't make a sound," he recalls.
"I had no idea where anyone was. No-one was crying, no-one was making a sound."
The atomic bombing of Hiroshima was one of the final and most drastic acts of World War II.
The United States had urged Japan to surrender or face utter destruction.
When the threats failed, the bomb known as "Little Boy" was deployed on the morning of August 6, 1945.
The city centre was immediately wiped out, with estimates of up to 80,000 people killed in an instant.
Many others suffered severe burns and would die soon after.
Mr Iida was lucky to have survived. The home he was staying in was only 900 metres from ground zero.
At the time, Mr Iida's grandfather was outside using the toilet, and was able to free his family from under the rubble.
"There were people whose clothes had burned away, their skin peeling off," Mr Iida recalls.
"If they tried to lower their arms, the skin would stick together.
"The next morning, at dawn, when I looked around, almost everyone was dead."
Ceremony to remember catastrophic fallout from world's first nuclear attack
Thousands of people gathered near ground zero in Hiroshima on Wednesday, 80 years after the bombing, to remember the catastrophic attack.
They had an overwhelming message: History must never be repeated.
With the number of survivors rapidly declining and their average age now exceeding 86, the anniversary is considered the last milestone event for many of them.
Representatives from a record 120 countries and regions, including Russia and Belarus, were expected to attend and observe a minute of silence with the sound of a peace bell at 8:15am, local time — the exact time when a US B-29 dropped the bomb on the city.
Hiroshima Mayor Kazumi Matsui, Japanese Prime Minister Shigeru Ishiba and other officials laid flowers at the cenotaph.
Survivors and their families started paying tribute to the victims at the peace memorial park at about sunrise, hours before the official ceremony.
In a speech, Mr Matsui warned of "an accelerating trend toward military build-up around the world", against the backdrop of Russia's invasion of Ukraine and the chaos in the Middle East.
"These developments flagrantly disregard the lessons the international community should have learned from the tragedies of history," he said.
"They threaten to topple the peace-building frameworks so many have worked so hard to construct."
In 1945, it wasn't just the fireball that caused carnage.
Radiation sickness also took hold, causing thousands to literally rot away while alive.
By the year's end, some 140,000 people were dead.
Those who survived radiation endured a lifetime of health problems. Many children in their mothers' wombs suffered birth defects.
Many survivors also endured discrimination in the years afterwards, as Japanese civilians feared atomic bomb survivors would be infected and create disfigured offspring.
Among the victims were thousands of Koreans who had been brought to Japan as forced labour during Japan's colonisation of the Peninsula.
Jin Ho Kim, 79, was exposed to radiation as an unborn baby. He's suffered various health problems, but it's proven impossible for doctors to confirm if radiation exposure is to blame.
"Not many people know the facts that so many people from the Korean Peninsula were exposed to radiation and died," he said.
"There were rumours that people exposed to radiation couldn't get married, couldn't find jobs, or couldn't have children.
"My parents had this rule that they absolutely wouldn't talk about the fact that they had been exposed to the bomb."
Just three days after the attack, the port city of Nagasaki was also struck.
Some 74,000 people died from the blast and subsequent injuries.
With the Soviet Union also declaring war on Japan, the emperor finally broke a political deadlock in his war council and announced the country's surrender.
The war was over.
Survivors call on world to eliminate nuclear weapons
Survivors of the atomic bombings are known as Hibakusha.
They led a campaign for compensation, initially winning medical costs, and then finally getting national financial assistance in 1981.
There's been another driving force uniting the Hibakusha: to push for a world free of nuclear weapons.
Last year, Satoshi Tanaka joined other survivors on a trip to Norway, where the Hibakusha were awarded a Nobel Peace Prize.
"We have two major demands," he said.
"To eliminate nuclear weapons, which are the root of all evil for humanity, and to prevent any more victims of nuclear weapons."
But with tensions in the Middle East, war between Russia and Ukraine, and China's threats of invading Taiwan, many fear the world is too close to another nuclear attack.
"How can we influence, even by a millimetre, a handful of leaders who hold the nuclear buttons?" he said.
"These are the very people who pay no heed to the Nobel Peace Prize, who turn a blind eye to it.
"We are calling on them to listen to the voices of the atomic bomb survivors."
The few surviving elderly Hibakusha are determined that their voice will never be lost, long after they've passed away.
"Most people have no idea about the power of the atomic bomb," Mr Iida says.
"Modern nuclear weapons are hundreds of times more powerful than those bombs.
"They're unusable."
ABC/wires
