Don't know why. Part of me wishes I did so I could stop it, but part of me is glad I don't.

All I have to go on right now are hunches. First hunch: these ghosts are connected to what's going to happen. Maybe see if you can talk to some ghosts and find out what's going on. Second hunch: people who treat each other decently don't get the sudden urge to kill each other. If there's anyone in town you don't get along with, try to patch things up, soon.