How would the “prank” have “gone right” in your view?
What pushed this over the line into a criminal assault is the “imminent fear” element of what they did.
If someone doesn’t see smoke or fire, and just hears the buzzer demanding evacuation of the building, then there’s no fear of “imminent injury” from the fire.
But telling the students that it’s “not a drill,” and having a disguised staffer come to the door and pull on it, is intentionally creating reasonable fear of imminent injury or death, and that’s a class A misdemeanor in Tennessee.
The teachers screwed up, pure and simple. They will pay for this mistake, as will the taxpayers.
Actually, we have 3 kids in the school right now that have anxiety disorders. Those kids are given warning of the fire drill before time and one is taken out of the building before it happens, and even then he paces back and forth wringing his hands with worry and saying "what if it's real this time - what if it's real this time."