WWII bomb in Cologne detonated in a controlled explosion

The western German city of Cologne has successfully carried out its most complex bomb disposal operation since World War II.

A 1,000-kilogram US bomb was detonated in a controlled manner on Friday evening, the city administration said.

The experts from the explosive ordnance disposal service were initially only able to defuse one of the bomb's two impact fuses in the afternoon. As a result, the unexploded bomb had to be detonated in a controlled explosion, which required heavy lorries to bring in large quantities of sand first.

Shortly before the conclusion of the operation, the city issued a precautionary warning: "The operation leadership points out that a muffled bang from the controlled explosion will be audible to the public beyond the 500-metre danger zone."

Approximately 6,400 residents also had to leave their homes in what city officials described as the most complex evacuation of its kind in Cologne since 1945. Traffic and public transport were also diverted from the area.

A city spokesman said that around 1,300 people were involved in total, including staff from the public order office, police officers, firefighters, rescue personnel and 800 volunteers.

Two of three hospitals in the area were fully evacuated on Wednesday and Thursday, the city said. In total, about 640 patients were affected, with most being transferred to other hospitals.

However, the intensive care patients at the third location, the Merheim Hospital, were relocated to a so-called safe house on the site itself.

This had been specially secured with thick wooden panels in the unlikely event that the bomb exploded during the disposal process.

The device was found on a site where a new health campus is planned to be built.

Bomb disposals themselves are a common occurrence in Cologne, as the city was one of the most heavily bombed during World War II.

On the night of May 30-31, 1942, the first "1,000-bomber raid" by the British Royal Air Force on a German metropolis took place.

The German writer Thomas Mann, then living in exile in California, noted at the time: "Terrible air raid on Cologne, 1,000 aeroplanes. Destruction and panic."

Approximately 20,000 people from Cologne lost their lives in bombings, and by the end, almost only the cathedral remained standing in the city centre.