In Colorado, many remembered the second worst school shooting in U.S. history, on Monday. It was 10 years ago, Monday, that two teenage gunmen carried out a methodical massacre at Columbine High School, in Littleton, Colorado. They murdered thirteen, before killing themselves. Though the pain may always remain, survivors are hoping to make this anniversary a turning point. ABC News’ Paula Haddock is in Littleton, Colorado with more on the big story.