Title says it all.

http://cloud.steampowered.com/ugc/1135164277611216948/2F28AE060795AC50D39707AF2209C68079B7BD0C/

I just got done with an online game. This little piece of terrain allowed our worms to fall through even though it seems to still be mostly intact. I blew up one of the other worms with a grenade, and the explosion sent him flying downwards through the land. Then later I walked on it, forgetting it was there, and I fell through as well.