Uncovering WWII Explosives: Challenges in Modern Urban Construction Sites

German city streets fell eerily silent as over 20,000 residents were forced from their homes in Cologne’s largest evacuation operation since World War II. The urgent exodus came after construction workers unearthed three massive American bombs from the war era, triggering a massive security operation to prevent potential disaster.

At a glance:

• Three unexploded American WWII bombs were discovered in Cologne, Germany, forcing over 20,000 people to evacuate

• The operation was the largest evacuation in Cologne since the end of World War II

• The bombs included two 20-ton and one 10-ton American bombs with impact fuzes

• The evacuation affected homes, hospitals, schools, train stations, and required closing three Rhine bridges

• Bomb disposal experts successfully defused all three devices within about an hour

Massive Evacuation Disrupts German City

Construction workers at a shipyard along the Rhine River in Cologne’s Deutzer Werft area made the alarming discovery of three American bombs from World War II. City officials immediately established a 1,000-meter evacuation zone, affecting over 20,000 residents in what authorities described as “the largest operation since WW2.”

The massive bombs included two American 20-ton explosives and one 10-ton bomb, all equipped with dangerous impact fuzes that remained active decades after being dropped. Explosive ordnance disposal experts from the Rhineland Explosive Ordnance Disposal Service of the Düsseldorf District Government were called in to handle the delicate operation.

The evacuation affected critical infrastructure throughout the city, including nine schools, daycare centers, a hospital, nursing homes, hotels, and government buildings. Three bridges across the Rhine, including the crucial Hohenzollern railway bridge, were closed, and all shipping on the Rhine was suspended during the operation.

20,000 people have been evacuated in Cologne following the discovery of unexploded WW2 bombs – here’s the Allied bombing of Cologne on film: https://t.co/oBTezrRHr8 pic.twitter.com/6GAJt4vSn6

— British Pathé (@BritishPathe) June 4, 2025

Operation Delayed By Resistant Resident

Despite the clear danger, the defusing operation faced a delay when one resident initially refused to leave their home in the historic center. City authorities were forced to take a firm stance, warning reluctant residents: “If you refuse, we will escort you from your home – if necessary by force – along with the police.”

More than 20,000 residents were being evacuated from part of Cologne’s city center as specialists prepared to defuse three unexploded U.S. bombs from World War II that were found earlier this week. This is Cologne’s biggest evacuation since 1945.

The bombs were discovered in the… pic.twitter.com/JKKM3i9CfC

— Anton Gerashchenko (@Gerashchenko_en) June 4, 2025

The city established two drop-in centers for displaced residents, advising them to “stay calm” and to bring identification, medications, and make arrangements for pets. Fifteen weddings had to be relocated due to the evacuation, and intensive care patients were moved from the Eduardus Hospital in the affected zone.

Kai Kulschewski, head of explosive ordnance disposal in neighboring Düsseldorf, emphasized the seriousness of the situation, stating, “We can only start when the last person is out.” Once the area was finally secured, the expert team successfully defused all three bombs within about an hour.

Germany’s Ongoing Battle With War Legacies

The discovery of unexploded ordnance remains a common occurrence across Germany, a haunting reminder of the country’s wartime past. Cologne was a frequent target of Allied air raids during WWII, with the first raid occurring on May 17, 1940.

The successful defusing operation was completed by 7:19 p.m. local time, allowing relieved residents to finally return to their homes. City officials confirmed that “Experts from the Rhineland Explosive Ordnance Disposal Service of the Düsseldorf District Government had rendered them harmless,” bringing the largest evacuation in Cologne since 1945 to a safe conclusion.