Columbine High School and Its Effects On Tuesday, the 20th of April, 1999, two students of Columbine High School in Littleton, Colorado moved through the hallways and classrooms of their school shooting other teachers and students at random. The two high school-seniors, Dylan Klebold and Eric Harris killed 12 students, one teacher and themselves that day, while injuring many others. This horrific incident has had a lasting effect on the history of this country. The president of the United States and Congress have tried many times to pass new gun bills. Many things have been done in the city of Littleton and the high school that have reflected a change in high schools