Back when dinosaurs ruled the earth and ipsc was beginning, We were told to set our digital watches to beep, at 1 or 2 hour intervals, and when that happened to look around and ask ourselves what if, that would become the scenario of the next match.
What I found was I got used to the beep, and would anticipate it ( like the alarm clock in the morning ) and begin looking 5 minutes before the watch sounded. This is the beginning of situational awareness. Where am I, what are my options for fight or flight? This made for many heated debates about what was practical and what was not. If your watch beeps and your in the heat of passion, or in church pew, it is valid, What if it happened now!!
The next chapter in the play is what our local constabulary calls being " Fat, Dumb and Happy " this is the state that most people around us live in, it would be nice if this was ok, and mostly it is, but that is not for us. Always aware, Always prepared, one way or the other. Stay and fight, or run away, depends on the situation, if being carjacked or led into a walkin refrigerator, fight like hell, because your adversaries want you dead, and your options are nil, armed or otherwise. If you see an out, take it and tell the Police all you saw.
I posted previously on the classroom scenario, and think, it was still a good observation, none of us want to be there on that day, but I think, superior mental attitude will rule the day. Uncle Jeff, bless his soul, said " make the decision to kill someone when you wake up in the morning " that way when the time comes, you have already made it, and you don't have to mentally process that information.
Rocks, books,, flagstaffs, tables or chairs, are the available weapons in most classrooms, use them as you see fit, and anything you can carry with you,, umbrella or walking stick is a bonus. It depends on the orientation of the room as to where I want to be be, perpendicular to the door with my back to the door is a lousy place so, put me against the far left or right wall... The door parallel to the desk arrangement,, put me 2nd row against the inside wall with the door fairly close, where I could jump up and address said asshole and subdue he or her. ( not recommended, but the best approach given the circumstance) .
For God sakes and yours, if you hear gunshots, tell your teacher and the class, get down, lock the door, and if that is not possible, pile things against the door, evacuate people from the windows, as fast as possible, be prepared for a fight and maybe turn the lights out and look small.
Bottom line, choose not to be victim.