14 December: the Sandy Hook Elementary School shooting
Between 9:35 and 9:40am on 14 December 2012, Adam Peter Lanza, a 20-year-old white male, murdered his mother and then drove to the Sandy Hook Elementary School in Newtown, Connecticut. With a Bushmaster XM-15 and a .223 caliber semi-automatic rifle, Lanza killed 20 children aged six to seven years old as well as six faculty members. Lanza then shot himself in the head. This incident was the deadliest mass shooting to take place at a school and the third-deadliest shooting by a single person in United States history.