apr 20, 1999 - APR. 20, 1999 17 and 18 year-old Dylan Klebold and Eric Harris killed 12 students and one teacher. Prior to the school shooting, the boys made a video detailing their plans, including ideas to bomb the pillars holding up the library over the cafeteria. IMPACT: Brought school safety to national spotlight and caused bans of backpacks and reuiquirement to carry IDs and upped police security at the schools. (Timeline)