Why did the Columbine Shooting happen? What was the purpose?

Question

I mean, I know Eric Harris and Dylan Klebold did it, but Why?

Why those specific 12 people?

Answer 1

Teens go through depression, some worse than others, and what they do during this depression can be fatal. The two kids who shot up their school, Columbine, became obsessed with violence, and this only fed their anger. This led to fantasies of killing, they wanted power, control. They carried out their fantasies on that fateful day.

Answer 2

Human life has been cheapened after all, people kill babies everyday. Also, (this is documented) video games make it easier to kill people.

Another factor is that people want fame more than anything.  They got it.