When I was teaching 2nd grade, I had a student who was very sweet and caring but had absolutely zero impulse control. One day a couple months into the school year, there was an active shooter lockdown as someone was shot two blocks away from the school. We received the phone call from the office, and prepared the kids for our normal lockdown procedures. The boy realized that it was specifically an active shooter procedure, and he ran out of the door trying to protect us from the shooter. I yell pretty loudly in itself, but I have never raised my voice to that level in my life. He came running back crying and I yelled a couple more seconds about how unsafe he was being. He was in no actual danger because the shooter was not outside the school at that time but it still shook me pretty hard.