That utterly sucks. I have a friend who teaches, and someone asked him at a holiday party, "But aren't you afraid of school shootings?"
That that should be someone's first thought when hearing that you teach is tragic, and that the logical response is, "But this is America. Mass shootings happen EVERYWHERE," just makes it worse.
Interpreting the Second Amendment as an unrestricted all-access pass to guns is clearly a terrible thing for our society. Feel free to post about this on the
imgflip.com/m/GunsKillPeople stream, and I hope you and your friends stay safe.