The worst US elementary- and secondary-school massacres before yesterday:
* Andrew Kehoe, a farmer crazed about taxes for schools, blew up a Bath Township, Mich., school on May 18, 1927, killing 38 children, two teachers, four other adults and himself.
* Twelve students and a teacher were slain when students Eric Harris, 18, and Dylan Klebold, 17, walked into Columbine HS in Littleton, Colo., on April 20, 1999, and opened fire with four weapons. They wounded 21 others before killing themselves.
* A truck driver, Charles Carl Roberts, fatally shot 10 girls, ages 6 to 13, then himself at an Amish schoolhouse in Bart Township, Pa., on Oct. 2, 2006.
COMPLETE COVERAGE OF SANDY HOOK ELEMENTARY SCHOOL SHOOTING
* Adrifter, Patrick Purdy, killed five children, ages 6 to 9, in the playground of an elementary school in Stockton, Calif., on Jan. 17, 1989, before turning his 9mm pistol on himself.
* On March 21, 2005, student Jeffrey Weise, 16, killed five students, a teacher and a guard at a high school in Red Lake, Minn., before taking his own life.
* Two students, ages 13 and 11, killed four girls and a teacher atamiddle school on March 24, 1998, in Jonesboro, Ark.