Then two figures in ski masks and ankle-length trench coats suddenly stepped to the door, produced pistols and semi-automatic rifles and opened fire. Boys and girls fell bleeding and crying. Others froze in fear and bewilderment for a moment then hysteria hit and they ran for cover.
But the killers were already loping up the stairs to the library throwing homemade pipe bombs behind them. The library was next. "All jocks stand up," shouted one. "We're going to kill every one of you."
The noise, the screaming and crying from downstairs told the terrified students this was not a joke. Someone asked the killers why they were doing this and one said: "People were mean to me last year." One girl tried to hide under a desk. "Peek-a-boo," said one of the two and shot her in the neck. Then they picked their targets, the "jocks" - the school's athletes , and students from ethnic minorities. One sobbing girl begged for her life. She was killed. Anyone who cried or moaned was shot again.
Nick Foss survived. He said: "When one of them looked at me, his eyes were just dead. But they were laughing after they shot. It was like they were having the time of their lifes."
To the boys and girls of Columbine High what made the horror of it so difficult to understand is that the laughing killers were two of their own. Eric Harris and Dylan Klebold were members of the school's "Trenchcoat Mafia" who took pride in being seen as irreverent outsiders. No one could have suspected that their studied eccentricity and half-baked vocal admiration of Hitler would explode in such murderous violence. Earlier that morning, Jenni LaPlante, 18, said the two had seemed perfectly calm at an early morning bowling class. But later Brooks Brown, who had been friendly with Harris met him and was told: " Brooks, I like you. Now, get out of here, go home." The shooting began soon after that. Brown said: "I took off and started running. I stopped at a house and told them to call the cops. I told them I knew who it was. It was Eric - it had to have been."
In the 1998 high school yearbook the "Mafia" had taken out an advertisement, saying, "Who says we're different? Insanity's healthy". That insanity was now spreading through the school. At 11.45 nine boys and three girls lay dead in the library. A member of staff who had tried to get in was blasted at close range, Outside the library panic-stricken students were running and trying to hide. They could easily have found themselves in a trap. Harris and Klebold had placed home-made bombs with timers around the school. Police later found more than a dozen.
A teacher, Mrs Miller, stopped students and shepherded them into the auditorium and they blocked the door with desks. Jake Cram, 18, said: "She ran up to us and said, 'Don't go that way. Go into the choir room and hide'. What she did was awesome, she is a hero, she saved our lives." As the 60 boys and girls huddled together, Harris and Klebold roamed the corridor outside, still shooting. Some girls began to hyperventilate and other students removed ceiling tiles to let in air.
Bree Pasquale, 15, said: "They ran along corridor asking people if they were jocks. If they were wearing a sports hat, they would shoot them." Jonathan Vandermark, 16, is only too aware how close he came to death. "They came up to me and asked if I was a jock and basically I lied. I lied and saved myself."
The police had been alerted at 11.25 and the first Jefferson County sheriff's deputies had arrived within five minutes. Police helicopters circled overhead and there was live television coverage. But no rescue attempts could be made because police feared hostages had been taken and rooms had been booby-trapped. But around 12.15 some students managed to get out. The wounded were taken to hospital in Denver.
Others were still hiding inside. They used their mobile phones to call their families and friends, the media and the police. One youth, giving a whispered interview to local television, was told by the journalist to call the emergency number 911. At one o'clock Swat teams in camouflage and body armour finally entered the school and began to sweep through the building. Half an hour later an armoured car was brought to the main entrance. At 2pm students began to come out with their hands over their heads because police feared the attackers may have forced students to swap clothes so they could escape. The students were searched, questioned, and taken in yellow school buses to a nearby junior school where relations and friends waited.
A pipe bomb had been found and there were reports of more. At 4.00pm three youths in black were arrested near the school. They were friends of Harris and Klebold and the police suspected them of helping organise the slaughter. More bombs were found at the car park.
The bodies of Harris and Klebold had already been discovered but could not be moved, because, police believed they had booby-trapped themselves. Bodies of victims could not be moved either for the same reason.
For those who had escaped there were tearful reunions with their families. But the town of Littleton will take a long time to recover from what happened at Columbine High.Reuse content