Four roses are placed on a fence outside Oxford High School in Oxford, Mich., honor Hana St. Juliana, 14, Madisyn Baldwin, 17, Tate Myre, 16, and Justin Shilling, 17, the four teens killed in the Nov. 30, 2021, shooting at the school.
Candles burn at a makeshift memorial near Columbine High School on April 27, 1999, for each of the of the 13 people killed during a shooting spree at the Littleton, Colo., school.
A group calls for additional school safety measures in Laurel County, Ky., on Feb. 21, 2018, following a shooting at Marjory Stoneman Douglas High School in Parkland, Fla., in which 14 students and three staff members died. Districts have invested billions in personnel and physical security measures in the 25 years since the 1999 shooting at Columbine High School in Littleton, Colo.
