The chance mistake that saved hundreds of lives on the day of the Columbine shooting.

Columbine High in Littleton, Colorado, was part of a peaceful community nestled between Denver city and the foothills of the Rocky Mountains.

That peace ended on April 20, 1999, when two teenage gunmen went on a shooting spree at the high school, killing 13 people before turning the guns on themselves.

The death toll was severe and the fall out from the killing spree is still rocking the community almost 20 years later.

But it could have been much worse.

As reported by The Guardian, if Eric Harris and Dylan Klebold had pulled off their original plan, the death toll would have been catastrophic.

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In the immediate days, weeks and months after the shooting the media, guided by misleading witness statements and general confusion, created profiles of the two suspects which were widely accepted for a long time.

We were told they were social outcasts who were bullied by the “jocks” and the popular kids. We were told they listened to Marilyn Manson and were part of a group called the ‘Trenchcoat Mafia’. And we were told their goal, when they entered the school that day, was to target specific students in an act of retribution for the way they had been treated throughout high school.

Years later we would learn that none of this was true.

According to Slate, confused student statements, along with a police cover up, had led the media to create the kind of narrative we wanted to hear.

People wanted to think the killers were social outcasts, from bad backgrounds, who had been tormented to the point where they snapped.

But this was just not the truth.

Harris, 18, and Klebold, 17, had plenty of friends. They did well at school. They didn’t even listen to Marilyn Manson and they certainly weren’t part of any so called Trenchcoat Mafia.

The truth was far more sinister and much harder to swallow.

Through Harris’s website and the boys’ private journals investigators uncovered a plot to blow up the entire school.

They weren’t specifically targeting anyone – the teen killers hated the world and wanted to annihilate as much of it as they could before taking themselves out.

Harris and Klebold’s plan was to detonate two propane bombs in the cafeteria, to not only kill the 600 or so students who were taking an early lunch but to also kill all of the students in the library above.

Once the bombs detonated, they planned to open fire on the rest of the students as they swarmed towards the exits.

In their big finale, they would drive their cars, which would be loaded with more propane explosives, into the descending rescue workers and media crews.

They hoped to take out 2000 people that day, not 13.

When their homemade bombs did not detonate, the killers were forced to improvise.

Dressed in long black coats, Harris and Klebold entered the school, killing two students on the way in.

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They then walked around the hallways, the cafeteria and the stairs before entering the library. In the library, they killed more students before turning the guns on themselves.

It would take the police almost three hours to discover the killers were already dead and the carnage was over.

In the years since Columbine, we’ve been left with many unanswered questions. Like how could police and the school not see this coming? What role did the parents play? And is there anything we can do to stop another Columbine from happening?

But probably the most haunting unanswered question has always been – how can two teenagers, who had a pretty easy life surrounded by family and friends, have such an intense hatred for the world they lived in?

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