You missed the point, Fredericks, "What should teachers and students do when someone enters a school with a loaded weapon and the intent to do harm?"  For example, the Sandy Hook Elementary School where 29 grade school children that were gunned down by an adult male assailant it what the article is getting at.  Colorado's Columbine High School shooters were adult-size male students.  Mass shootings have been know to be adult shooters.