Use cell phones to communicate with the security office to find out how many intruders, weapons, and other information in real time. Next step is to wait have the students hide within the classrooms. Lock the door and wait. If the weapons are explosives, have people evacuate from the windows and if they are guns wait for them to try and get into the door. When the barrel of the gun enters the door, smack it down and grab ahold, the gun will go off and will burn you but you have to hold on. With the barrel in you hand, use the other hand and feet to attack soft areas. Claw out eyes, throat, groin, solar plexus and others to wrestle the weapon away. Jump back, shoot the intruder, rinse and repeat until the cops arrive.