Students across the country walked out of class for 17 minutes at 10:00 a.m. Wednesday morning in a mass protest against gun violence in the wake of the school shooting in Florida last month. The demonstration came exactly one month after the shooting and the 17-minute duration represents the 17 people who were killed. At Columbine High School in Colorado, students added 13 minutes to their protest to represent the victims of the 1999 shooting at that school. Keep reading for more news.