To answer Navpi, I've dealt with several German air-dropped bombs during my time in the service, and to my knowledge none have exploded in UK in recent times except those deliberately detonated by EOD teams. A worker in Germany was killed in 2014 by a (believed to be) USA munition detonating when disturbed, which illustrates that the risk is very real. (There are far more UXB in Germany than other countries for fairly obvious reasons, and their EOD teams are utterly professional). Once the fuse is deactivated and removed the bomb itself is usually stable enough to be lifted and moved to a safe place for disposal, normally by detonating the main charge -if you ever experience one of these you gain a healthy appreciation of the amount of damage it could inflict in a built up area.