20 years on, Columbine survivors and victim's father offer words of encouragement to their younger selves

CBS Mornings April 18, 2019 / 8:33 AM EDT / CBS News Columbine shooting, 20 years later On April 20, 1999, two gunmen killed 12 students and one teacher at Columbine High School in Littleton, Colorado. Amy Over was a senior at Columbine. Kacey Johnson, was a junior. Tom Mauser's son, Daniel, was a sophomore.Now, nearly 20 years later, we asked these members of the Columbine community to reflect on the two decades since the shooting, in notes to their younger selves.Below are Kacey Johnson, Amy Over andTom Mauser's full notes, which which were edited for time on "CBS This Morning." Kacey JohnsonDear Kace, For the first time in your life, you feel confident. You've overcome loss and depression and are now starting your junior year at a new high school. This summer, you are planning to represent Colorado in the World Quarter Horse Championships. But you won't make it there. Your world is about to change in the most unpredictable way.Today will be like any other school day until, instead o...