We been looking for those ...

Yes But Who's

High yield explosives of that age are highly unstable and the simple process of mechanically fining them may have 'upset' them. There is some dispute as to if Allied forces used delayed timers on 'normal' bombing raids.
It is very sad to think these devices are still killing people. On top of the loss of life we have also lost a great deal of bomb defusing experience.

The WWII stuff is not nearly as bad as what has been done since - Millions of land mines and cluster bombs. Killing potential Mozarts and Einsteins Daily.

Dragon Heart wrote in news:84866dfa-3952-4519- snipped-for-privacy@r5g2000yqr.googlegroups.com:
The RAF did as a matter of course, the idea being to kill valuable rescue workers moving into the area after the raid.
Generally speaking the raids on city areas went like this ...
First wave - pathfinders would drop target markers, these were very large incendaries that detonated in the air, the filling was burning rubber and the like.
The next wave in would drop heavy bombs like "cookies", the idea being to fracture gas mains (to provide additional fuel) and fracture water mains with them would be droped MC GP bombs - "simple" explosives to bring down and open up buildings.
The next wave would drop lots of incendaries to set fire to the now opened up buildings, mixed in with them would be further GPs to stop firefighting attempts.
If it as a really big raid there would be two further waves, the first of which would have lots of GP bombs to stir up the buildings again - bring new fuel to the surface with a smaller proportion of incendaries to keep the fire stoked.
The last wave would again contain lots of incendaries to burn up whatever was left to burn and take out what was left of any oxygen in the atmosphere.
A proportion of bombs from each wave would have delayed action fuses.
The Germans did the same to us (and everyone else they fought from the Spanish civil war onwards) but we did it better.
Seconded