Been to 2 forts yesterday around Luik ( Belgium ) the 2nd one was build around 1888 after the French/German war. The people defended it pretty good at the start of the First World War but a 420mm shell from a Big Bertha blew up a munitium room exploding 12.000 kilos of black powder. This offcourse gave a big mess, see the next link for pictures:
http://www.magneet.org/images/thumbnails.php?album=29
The first fort was finished in 1936 and was build with the lessons learned in the First World War. Too bad the Germans where aware that it was a good fort and decided to land glidertroops with a new bomb > the hollow mine that works just like a hollow point bullet but then with 12,5 or 50kgs of explosives. Below are some pictures of that. The pics where you see the big mess : this was after a 50kg hollow mine exploded 20 meters or something above on top of a artillery turret.
http://www.magneet.org/images/thumbnails.php?album=30
