User blog comment:Darkcloud1111/Good Idea, Bad Idea~Mountain Glenn/@comment-5217560-20141013022054/@comment-5217560-20141013031241

It does appear that leaving the city would have been a better option, but I think the distance between mountain glrnn and vale was too great. The subway might have been their only mode of transportation, so to them it was safer to just go underground than attempting to travel out in the open terrain like that. The subterranean grimm was just a random and unfortunate event. In trying to expand the cavern, the good people of mountain glenn just ran across the grimm. Who just happened to be occupying a space next to the city.