Mass shootings at schools, from elementary schools to universities, constitute a much-discussed subcategory of mass shootings.
Perhaps the most infamous mass shooting in modern U.S. history took place at Columbine High School near Littleton, Colorado, on April 20, 1999 (13 dead).
Other recent incidents of note:
Like other kinds of mass shootings, school shootings are not confined to the U.S. Selected examples:
From the Washington Post, a news article with infographics.
This report by an anti-gun violence advocacy organization attempts to track similarities in school shooting incidents.
Attempts to list shootings starting with 1840. However, many of these would not qualify as mass shootings.
Report by the Secret Service, FBI, and U.S. Dept. of Education, April 2010
FBI report. Not dated, but based upon a July 1999 symposium. Includes analysis of the characteristics of school shooters.
