Columbine school shooting victims remembered at 25th anniversary vigil CBS NewsColumbine 25 years later: We remember the 13 lives lost FOX 31 DenverColumbine shooting victims remembered 25 years later Yahoo! VoicesNearly 500 People Have Been Killed in School Shootings Since Columbine NewsweekColumbine’s legacy – schools remain in the crosshairs: Reporter’s notebook ABC News