Oh, heh, this could be a scene from so-called Hölmöläis village. See, there are finnish humoristic folktales about Hölmöläiset people, which translates as simpletons, or goofies, or loonies. In the tales Hölmöläiset/simpletons live in their own village and do stupid things over and over again.
But well, seriously, I'm thinking what was their incentive to go on the ice. Had you visited this village before, or did you just find it like this?
This might be related to NPCs wandering further away thingie:
http://www.unrealworld.fi/forums/index.php?topic=7252.0..but NPC should should still avoid thin ice.