10 years ago, the Columbine school shootings...

Teenage gunmen spilled the blood of children before Columbine, in Alaska, Arkansas, Mississippi and Oregon. After Columbine, more blood was shed in Minnesota and California, in Germany and Finland.

But none of those incidents cast a shadow as long or dark as the rampage at Columbine High School, where 13 people were gunned down 10 years ago Monday.

Eric Harris and Dylan Klebold, seniors at the suburban Denver school, detonated homemade bombs and opened fire with shotguns, a rifle and a semiautomatic handgun on April 20, 1999. They killed 12 students, injured 23 others and mortally wounded a teacher before committing suicide. More...

See also:

1. Anatomy of a School Shooting...
2. Global school shooting timeline...
3. Tim Kretschmer, another "normal" boy goes on a shooting rampage...
4. Seung Hui Cho and Virginia Tech ... one year later.