School security

Since 1999, American schools have tried to prevent a threat that had once been unthinkable.
On 20 April 1999, two teenagers entered Columbine High School in Colorado with guns and explosives. They killed 12 students and a teacher, before turning their weapons on themselves. The event changed American classrooms forever, with school security becoming a multi-billion dollar industry. Now that many Columbine shooting survivors are parents themselves, they are facing the repercussions of the tragedy everyday.