I saw a video that the city of Houston, Texas had recently completed about how to respond in an emergency situation with a gunman. The video shows a group of people who appear to be office workers talking together and organizing to assault a gunman when he comes through their door. The information from the video is that it is better to organize and fight the gunman to try to survive. Like "stop, drop, and roll", the phrase to remember if on fire, this catch phrase in a shooting emergency is "run, hide, and fight." The thinking is that anyone who is shooting up the place with a gun needs to be avoided and then stopped.
Do you almost want to say "What is our world coming to these days?" We should remember that this is a frightening topic, but thinking in advance about what to do in a crisis is always helpful for folks when they find themselves in that crisis. The phrase "run, hide, and fight" might indeed help someone in a difficult situation in the future.
I am hoping that your teen never has to put this slogan into effect.