Haunted Footage on Instagram: "On April 20, 1999, the quiet suburb of Littleton, Colorado was shattered by one of the deadliest school shootings in U.S. history. Inside Columbine High School, two students—Eric Harris and Dylan Klebold—unleashed a meticulously planned attack armed with firearms and homemade explosives. For nearly an hour, terror consumed the halls. Twelve students and one teacher were killed, more than twenty others wounded. Classrooms became barricades, libraries turned to hidin