I confess that the shootings in Virginia have hit me close to home. You can't teach for more than a month without encountering at least one student who worries you. In my time I've had quite a few, and there's one about whom I still have nightmares. (If I turn up dead, his name is one that should be investigated. I'm serious.)
Education becomes so personal, so intimate and yet because of its cyclical nature, it's easy for faculty and staff (and administration) to hope that "if I just get through this semester, the problem will be over." The problem forgotten by faculty will almost certanly live on for the student - heck, I'm still annoyed at the unprofessionalism of a prof I endured my freshman year.
I teach in a building with stout doors, ones that lock when closed. Since Monday I have faithfully closed (and thus locked) them at the start of class. So what did I do today? When someone knocked at the door, I opened it.