Adapt

Schools in @,:m3 Ri Ca have widely known drills for many scenarios. One of them involves school sh00 t3..r5.

Common procedure is basically to turn off the lights and hide under your desk or in a corner. That's just not going to work.

That something that would only work if the attacker had no idea about it. This is however impossible with how wide spread these drills are.

Things like objects to barricade entrances and guides on that would be significantly more useful.