Twenty years after Columbine, Colorado schools are assessing an astonishing number of student threats

4/10/2019–Colorado Sun investigation to mark the 20th anniversary of the 1999 Columbine shooting found the number of threat assessments at Colorado school districts has surged in recent years, multiplying more than tenfold in some districts. School officials say they are a necessary step to prevent student violence of all types, including the worst-case scenario, a mass shooting like Columbine, which left 13 victims dead and woke the nation to the possibility that classrooms could become killing grounds. Read