Columbine remembered

A look back at the April 20, 1999, shootings at Columbine High School in Littleton, Colo.

Eric Harris, left, and Dylan Klebold, carrying a TEC-9 semi-automatic pistol, are pictured in the cafeteria at Columbine High School, in Littleton, Colo., during their April 20, 1999, shooting rampage where they killed a teacher and 12 students. Both gunmen later killed themselves in the school library. Jefferson County Sheriff's Department / AP
In this image taken from TV, a student is rescued by emergency personnel during the shooting spree at the school in the southwest Denver suburb. KCNC-TV / AP
Columbine High School students at the triage scene. George Kochaniec Jr. / Rocky Mountain News via Newscom
An unidentified woman looks at 15 crosses on a hill above the school in Littleton, Colo. -- one cross for each of the people who died during the shooting rampage, including the two gunmen. Eric Gay / AP
A woman cries after writing on a casket containing the body of Rachel Scott at funeral services in Littleton on April 24, 1999. Scott was one of the 12 students who died in the attack. Rick Wilking / AFP
Columbine students embrace as they enter the high school after a "take back the school" rally Aug. 16, 1999. With cheers and words of hope, nearly 2,000 students, many wearing T-shirts declaring "We are Columbine," returned to school for the first time since the deadly rampage. Eric Gay / AFP/Getty Images
Five months after the attack, Pat Ireland does physical therapy with Brain Trzaskos, RPT, at Craig Hospital in Denver. Ireland gained fame as "the boy in the window" after he made a life-saving plunge out of the school library. Shot twice in the head and once in the foot, Ireland landed in the arms of Lakewood SWAT team rescuers. Linda McConnell / The Rocky Mountain News via Newscom
Columbine shooting victim Valeen Schnurr acknowledges the cheers as she leaves the stage -- diploma in hand -- during graduation ceremonies the year after the attack. Marc Piscotty / Rocky Mountain News via Newscom
Roger Kovacs and his wife, Lesli, visit a memorial at Chapel Hill Memorial Gardens in Littleton on April 20, 2007, the eighth anniversary of the massacre. Ed Andrieski / AP