Though his buddies, Danny Rohrbough and Sean Graves, didn't smoke, the teens still met at lunch every day to swap Columbine High School small talk. Twenty-two steps above them, at the top of an ...

It has been nearly 20 years since the first mass school shooting in the U.S. -- the shocking tragedy at Columbine High School in Littleton, Colorado, on April 20, 1999. As a “credible” threat ...