It is estimated that about one in ten bombs that the Allies dropped on Germany during the Second World War failed to detonate. There is a special word for them in German: Blindgänger. More than seventy years after the end of the war, there are between 135,000 and 270,000 tons of unexploded bombs remaining in Germany’s soil – some buried deep beneath the surface, others barely covered. All of them continue to pose a deadly threat.
One such bomb remained hidden for more than 72 years. A British HC (‘High Capacity’) 4000 bomb, which contains about 1,400 kg of explosives, was found near the University of Frankfurt during building works in the summer of 2017. It resulted in the biggest evacuation of post-war Germany to date. Had it detonated, the blast wave would have caused damage to houses and infrastructure for about a mile around.
More than 60,000 people were evacuated from their homes while bomb disposal experts got to work. This was a huge logistical undertaking, which involved clearing two hospitals and ten old people's homes, closing roads and schools and suspending public transport.
That same weekend, bomb disposal units also had to get to work in Koblenz, where a 500 kg US bomb had been discovered during the building work for a kindergarten. Approximately 21,000 people – a fifth of the total population of the city – were evacuated while the bomb was being made safe.
In Frankfurt, the experts managed to diffuse and safely remove the bomb – but many more remain today. As time passes, they become more dangerous, as metals corrode and chemical reactions inside the bombs threaten to trigger spontaneous explosions.
Before this latest evacuation, Augsburg had held the record for the largest evacuation of its citizens – some 54,000 had to leave their homes in December 2016. The cause was the same type of device that was found in Frankfurt: a British HC 4000. In May 2017, 50,000 inhabitants of Hanover were evacuated while three bombs were being made safe.
Unexploded bombs are an inescapable fact of life in post-war Germany. In Cologne, for example, anyone wanting to build in the city is required to prove that the site is free of bombs. Specialist bomb-disposal units work with building companies, using aerial photographs from the war to identify potential areas where unexploded bombs may still be hidden – small craters of two metres or less hint at such bombs, whereas large ones indicate a successful detonation. Once such a suspicious area has been identified, it’s time for the metal detectors. The aerial photographs are kept under lock and key, not least to prevent laypeople from trying to uncover these deadly remnants of the past themselves.
Unexploded bombs from the Second World War continue to pose a threat to civilian lives in all combatant countries. But Germany, whose towns and cities were near-obliterated in the final months of the bombing campaign, undoubtedly pays the heaviest price as experts predict that there may never be an end to the need to clear unexploded bombs from German soil.