2All combatants of WW2 left their "calling cards", including us.
My uncle was a Chief Warrant Officer, explosives/demolitions expert, serving- directly under Gen Patton at the 2nd battle of the Kasserine pass in North Africa.
Remnant explosive devices are still killing people in North Africa, especially in the area of the Kasserine Pass..
https://www.youtube.com/watch?v=LE861BMsOH8 He and his fellow munitions deactivators disarmed thousands of mines and bombs...but they didn't get them all.
When I was a young teenager, my uncle explained some of the things he dealt with, such as the "butterfly bomb".
The "butterfly bomb" was not hard to find, since they normally laid on the surface, having been dropped by the the
Luftwaffe..in the thousands.
The bomb opened and had little round "butterfly wings", which= turned as a screw on the detonator. Having been variously preset, some exploded before the hit the ground, other were still potent as laying on the ground.
In some cases of course, the threads were only a tiny fraction of an inch before exploding...just a touch could
set them off, no way of knowing..
http://www.inert-ord.net/usa03a/usa6/bfly/index.html Then there was the "bouncing Betty"..which was a mine which we were trained to disarm in my basic training in 1955.