History Book on Instagram: "On April 20, 1999, a mass shooting occurred at Columbine High School in Littleton, Colorado. Two students carried out an attack that resulted in the deaths of 12 students and 1 teacher before the perpetrators took their own lives. The tragedy shocked the United States and the world. Columbine became a turning point in how societies discuss school safety, youth violence, and mental health, leaving a lasting mark on modern history. This was not just a local event — it r