Chilling map shows what would happen if the Hiroshima bomb was dropped on London

A map showing the blast radius of a ‘Little Boy’ bomb explosion in London (Picture: Metro.co.uk)

At least 76,000 people killed and more than 245,000 wounded. Westminster Palace, Downing Street and Buckingham Palace obliterated.

This would be the aftermath of an atomic bombing on London, similar to the one on Hiroshima during the Second World War.

Today, August 6, marks 79 years since the US president Harry Truman deployed a nuke on the Japanese city in 1945 – a decision that changed the course of history.

To date, the bombs dropped on Hiroshima – and in Nagasaki three days later – are the only two such weapons used in a war.

By modern day standards, the bombs – codenamed ‘Little Boy’ and ‘Fat Man’ – are considered small.

As nuclear-powered states, Britain, Russia, US, France, China, Pakistan, India, Israel, and North Korea, get involved in more conflicts, there are fears that the world has not learnt lessons from the catastrophe in Japan.

The devastation caused by the atomic bomb dropped on Hiroshima (Picture: Getty)

What would happen if a bomb went off in London?

Nuke Map, created by Alex Wellerstein, a nuclear historian at the Stevens Institute of Technology, shows what would happen if a bomb like the ‘Little Boy’ explodes in London.

The number of fatalities is put at 76,470, but modeling casualties from a nuclear attack is difficult and it is not definitive.

Fallout effects are deliberately ignored, because they can depend on what actions the government takes after the detonation.

Another website, from the Outrider Foundation, puts the number of people killed at just above 30,000.

This also depends on whether the weapon detonates on the ground, or in the air.

The mushroom cloud over the Japanese city in the aftermath (Picture: Shutterstock)

A map created by Metro.co.uk shows the fireball in London. In the first millionth of a second after detonation, the bomb materials heat up to unimaginable and extreme temperatures.

The fireball forms immediately from the burning bomb residue. Anything – or anyone – inside the fireball would be vaporised in an instant.

Even outside this boundary, the heat would be intense enough to kill everyone.

Within the green circle, the dose of radiation would likely be deadly in about one month. And at least 15% of survivors will eventually die of cancer as a result of the exposure.

Most buildings would collapse, even within the ‘moderate blast damage’ radius. Injuries would be universal and fatalities widespread, Wellerstein warns.

Survivors of the explosion suffer the effects of radiation (Picture: Getty)

People in the ‘third radiation’ boundary would suffer third degree burns. They can cause severe scarring or disablement, and can require amputation.

What happened in Hiroshima, and then Nagasaki?

The atomic bomb dropped by the US on Hiroshima destroyed the city. More than 140,000 people were killed. A second bomb dropped three days later on Nagasaki killed 70,000 more.

Relations between Japan and the US had deteriorated in the years before, leading to an attack on Pearl Harbor in December 1941, in which Japan sunk several ships and destroyed hundreds of planes.

Their aim was to cripple the US fleet in the Pacific fleet. After entering the White House, president Truman took the decision to bomb Japan, in favour of an on-the-ground invasion.

The result of the detonation of ‘Little Boy’ was approximately 80,000 deaths in just the first few minutes. Thousands died later from radiation sickness in Hiroshima.

Japan then surrendered on August 15, finally putting an end to the Second World War.

What lessons has the world learned since?

Japanese officials urged world leaders today to stop relying on nuclear weapons as deterrence and take immediate action toward abolishment – not as an ideal, but to remove the risk of atomic war.

Hiroshima governor Hidehiko Yuzaki said nuclear-armed nations and supporters of atomic deterrence ‘deliberately ignore… the fact that once people invented a weapon, they used it without exception.’

During an anniversary service at the Hiroshima Peace Memorial Park, he said: ‘As long as nuclear weapons exist, they will surely be used again someday.

‘Nuclear weapons abolition is not an ideal to achieve far in the future. Instead, it is a pressing and real issue that we should desperately engage in at this moment since nuclear problems involve an imminent risk to human survival.’

Mayor Kazumi Matsui said Russia’s war on Ukraine and the worsening conflict in Palestine are ‘deepening distrust and fear among nations’.

Get in touch with our news team by emailing us at webnews@metro.co.uk.

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