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: