There have been 142 school shootings in the U.S. since 20 children and six adults were killed at Sandy Hook Elementary School in Newtown, Conn. on Dec. 14, 2012. Incidents were classified as school shootings when a firearm was discharged inside a school building or on campus, as documented in news accounts. Incidents in which guns were brought into schools but not fired, or were fired off school grounds after having been possessed in schools, were not included. Click for Map of Shootings!