My mother, sister, aunt, brother-in-law, and two first cousins are teachers, and I would be sick if the answer the state offered them for safety was a holster and a firearm. That is absolutely insane. Teachers are rarely trained properly to deal with a fight, especially at the secondary level where some students are the size of large adults, so asking them to confront an armed gunman is, not to use a crass phrase, WAY above their pay grade.
That is not a fair thing to ask of educators. It's the job of law enforcement.