An unexploded American World War II bomb caused 16,000 people to be evacuated from the German city of Frankfurt on Monday morning after it was discovered by workers on a building site.

The evacuations took place near the European Central Bank to allow an ordnance disposal team to deactivate one of the 1,100-pound bomb’s two detonators. It was dropped by the United States Army Air Forces (USAAF) at the height of the European campaign in 1944/45.

The bomb was discovered during construction work last month and detonation was scheduled to minimize potential disruption of the city, which acts as the country’s financial capital.

WWII two bombs are still commonly discovered in places throughout Germany 75 years after the war.

In April, 2,500 people were evacuated from central Cologne as a bomb weighing as much as 880 pounds was defused.

Divers with the city’s fire service were participating in a routine training exercise when they found the 250kg (550lb) device. Parts of the old town around Frankfurt Cathedral were affected, as well as the opposite bank of the Main.

Mit einem lauten Knall und einer riesigen Wasserfontäne ist am Sonntag die #Weltkriegsbombe im Frankfurter Main auf spektakuläre Weise unschädlich gemacht worden. pic.twitter.com/Ib5lnAljDG — hessenschau (@hessenschau) April 14, 2019

In 2017, German police defused a 1.4 ton World War II bomb (HC 4000 air mine) in central Frankfurt, after some 60,000 people were evacuated.