Movie about mother and daughter trapped

Okay so I don't remember much about the movie. I do remember a few things but not enough to be much help!

Made on or after 2000 (not a super old movie but actual age unknown)

A teenage girl is a recent victim of s.a. or assault or something and she is trapped in a building with the guy who hurt her

Very few people believe her because the guy is "popular"

She is trapped with a parent (I think it's her mom but might not be)

There is a fog or mist or something that hides monsters or creatures that kill the people so they can't escape

IDK how to hide spoilers!! The ending shows a few people escaping and there are a bunch of prisoners getting off a train and they are being fed to the monsters by soldiers