A student at Santa Fe, Texas, high school allegedly killed at eight to 10 people, most of them fellow students, on Friday morning before being arrested, the Harris County sheriff said.
Below are some of the bloodiest and most notable shootings in U.S. schools and colleges, ranked by death toll. This is not a complete list of all school shootings:
VIRGINIA TECH, April 16, 2007 - A gunman slaughters 32 people and kills himself at Virginia Tech, a university in Blacksburg, Virginia.
SANDY HOOK, Dec. 14, 2012 - A man shoots his mother to death, then kills 20 children and six adults before killing himself at Sandy Hook Elementary School in Newtown, Connecticut.
PARKLAND, Feb. 14, 2018 - A former student at Marjory Stoneman Douglas High School in Parkland, Florida, opens fire with an assault-style rifle, killing 17 students and educators. Authorities arrest the gunman.
AUSTIN, Aug. 1, 1966 - A sniper perched in a University of Texas clock tower unleashes 90 minutes of terror by killing 13 people and wounding more than 30 others in what is regarded as the first U.S. mass shooting in a public space. He is fatally shot by police.
COLUMBINE, April 20, 1999 - Two teenagers rampage through Columbine High School in Jefferson County, Colorado, fatally shooting 12 students and a teacher and wounding more than 20 others before killing themselves.