Almost 70,000 people have been evacuated ahead of a bomb defusal in Frankfurt. It is the largest post-war evacuation in Germany. Two major hospitals and several retirement homes had to be evacuated completely. The unexploded British World War Two bomb was discovered during building works. Bomb disposal experts will attempt to defuse the 1.8 tonne bomb remotely from a safe distance. It is estimated that 150,000 bombs still lie unexploded in the ground in Germany.