I'm not sure how to apply that to this situation, but it is one every school should think about when students try things.
If I think of my school time, I would believe even the fact that a bomb threat would be an annoyance to teachers would a be sufficient reason (of course, in the schools of the country where I live there were other methods than bomb threats to be an annoyance to teachers).
The military moved away from using urban armories. These became repurposed as sports halls, places for events, and so on. For examples, https://fightingillini.com/facilities/ui-armory/5 and https://www.wakefieldma.gov/Facilities/Facility/Details/Dril...
Solution is to make school non mandatory!
The obvious unintended consequence of this is that then nobody learns how to read (because who wants to go to school?) and then our economy crumbles and everyone is stupid and then everyone dies.
Or maybe some kids do go to school, so they become the global elite while the other 98% are illiterate and they flee the country because obviously and so the economy still crumbles and everyone dies.
See, these are the things we need to be thinking about.