Dylan Klebold, 17, and Eric Harris, 18, had a plan. Obsessed with violent video games and paramilitary techniques, they spent a year collecting an arsenal of semiautomatic guns and homemade bombs with which to perpetrate a crime that the nation would never forget.
Dubbed "the Trenchcoat Mafia" for their habit of wearing black trench coats, the boys had long been bullied and scorned by classmates, so they decided to flex a little muscle. Having no particular reason to live, they decided to kill themselves, but in the process they also wanted to kill as many of their classmates as they could and blow up the school.
The day before their rampage, they sent an email to the local police declaring that their revenge against those who ridiculed them had been accomplished. They blamed parents and teachers for turning their children into intolerant sheep, and then announced their own suicide. It was a bizarre forewarning.
At 11:30 a.m. on April 20, 1999, they hid weapons and bombs beneath their trench coats and then ran through the school, yelling and shooting. When they reached the library, they cornered and killed their largest number of victims before turning their guns on themselves. It all happened quickly, but with devastating impact. After police got into the building, they counted 34 casualties. Fifteen students died in the melee, including the shooters.
Then Harris's diary turned up, which confirmed how elaborately they had planned the shocking event. For over a year, they worked at it, drawing maps, collecting weapons, and devising a system of silent hand signals for coordinating their moves. They'd purchased the guns via Harris's girlfriend at a gun show.
The final report indicated that the two were part of a larger organized network, and that their motives and ideas were intense, but confused. In short, they appeared to have been angry, bitter kids who had access to guns and who were spurred by images of violence to act out their anger against those they most detested—classmates who fit in better than they did.
Yet the Columbine massacre didn't stop there. Not only did a mother of one of the wounded walk into a gun shop and proceed to shoot herself in the head, but a 17-year-old student was jailed for threatening to "finish the job."
In fact, around the country there were a number of copycat overtures that closed down schools in several states, and eventually one of them succeeded.