In this April 20, 1999, file photo, women head to a library near Columbine High School where students and faculty members were evacuated after two gunmen went on a shooting rampage in the school in the Denver suburb of Littleton, Colo. Twelve students and one teacher were killed in a murderous rampage at the school on April 20, 1999, by two students who killed themselves in the aftermath. (Photo by Kevin Higley/AP Photo/File)
