This cannon fires water cooler tanks to rescue shooting victims.

[Crimor]

Ranged shaped charges would be a bit expensive(Though the idea behind a HEAT round could be scaled back a bit since it doesn't need to pierce armor in this case), but placable "Door makers" have existed for decades, some even being nothing but detcord and a plastic casing you fill with water to block most of the unintended blast directions.

[IAmIroningMyDog]

what if we blow up the school instead

that way we wouldn't need emergency exists, because everywhere is an exit now

[angelangel]

a very american solution to a very american problem...

[Blueleaf]

Imagine hiding in fear from a school shooter, panicing at any slight sudden noise or movement made, and then suddenly a fucking water cooler just slams through the wall at 60mph and sends debris flying everywhere.

Even if I didn't immediately get clobbered in the face or cut by debris I'd be bricking myself.

[Resonant]

https://www.youtube.com/watch?v=sUPlSZucdJk