Okay, so how many times are students going to press the panic button to get out of school early?
I assume it/they will be located in the admin offices — probably under a locked cover to prevent accidental pushes.
[enter armed invader]
[Admin Barney Fife approaches, challenges, gets taken hostage.]
Witness: We have an armed invader. Someone push the panic button.
Admin aide: Okay, who has the key to unlock it?
Voice in the distance: Mr. Fife has the key.
Admin aide: Oh. Okay. Someone stick your head out the window and yell REALLY LOUD for the police.