Load Toad
I worked in Germany in the 1980,s and on the project we found a large allied bomb (bit like an emersion heater). The Luftwaffe Lt who came to disarm it said it was a Block buster designed to blow the roofs off buildings to allow incendiary bombs to get into the inside of them. He was very matter of fact about, and did point out that there was a very high failure rate on allied bombs 20+%, which apparently was down to poor testing. Our testing was carried out up in Scotland with bombs falling onto rock where most German cities are built on softer ground so bombs tended to get buried rather than explode. At that time he said they were still getting many calls per year (this was in Munich) and his colleagues in the Ruhr were still busy.
Regards
Mr Mac