[LTSR]

The Rhine was the last major physical barrier to the Allied advance into Germany and the Ludendorff Bridge was the only crossing point remaining standing.
The bridge survived for about ten days after its capture before it succumbed to the damage it had sustained.
Both sides had tried to destroy it, the Americans to prevent the German forces still on the west bank from escaping before realising its importance as crossing point and the Germans to prevent the Americans establishing a bridgehead.

 

[LTSR]

Very true about the depth things can get buried; the forces involved are pretty awesome.

A while back there was a programme on the TV about a 'dig' in London, it seems Flight Sergeant Ray Holmes having inoperative guns deliberately flew his Hurricane into a German Do17 bringing both aircraft down, an act of valour witnessed by many on the ground. He managed to bail out injured before his 'plane crashed; the engine was recovered during the dig from something like 25 feet (7.6 metres) beneath a roadway near Buckingham Palace.