It depends where you are at the time. if its happening like right in front of you then you have no choice but to hide like a flip over a desk or open a cabinet door and stay in cover, not necesarily under anything because i mean they can see you still. i would think they would shoot you if you tried running in front of them especially if theyre in the doorway and ofc whoever your dealing with a trespasser with no intention who they shoot or a schoolmate who might have plans.. If you are just close to where the shots are being fired just run and exit try to get outside, thats the last place the shooter wants to go is outside..dont listen to anyone telling you to stay put because if you can run out run out.