More than 311,000 children have been exposed to gun violence at 331 schools since the Columbine shooting.
Frank DeAngelis, or “Mr. De,” as his students called him, had been principal of Columbine High School in Littleton, Colorado, for three years on April 20, 1999. At 11:19 a.m. that day, two seniors came to school armed with semiautomatic rifles, pistols and explosives. They killed 13 people and wounded 21 more.
