A 4,000lb High Capacity Unexploded Bomb (UXB) prompted the evacuation of more than 60,000 people in Frankfurt on Sunday. The British bomb, found during construction works the previous week, was defuzed by an Explosive Ordnance Disposal (EOD) team after a 1.5km evacuation cordon was put in place.
UXB finds in Germany are a regular occurrence and, unlike in the UK, there is legislation in place to ensure that all construction projects consider the possibility of encountering Unexploded Ordnance (UXO) and put suitable measures in place to mitigate any risk.
See: http://edition.cnn.com/2017/09/03/europe/germany-frankfurt-bomb-evacuation/index.html