In the event of a school shooter, I was told to run and hide in the corner away from any windows and lock any entrances. If I was in the restroom, I was out of luck. If I was in a hallway, I had to hope that a teacher would open the door to let me in and hide with them.
When I experienced a gun incident, all of the rules went out the window, and the fear of being shot crept inside my mind.