Columbine Massacre by Viktor Bunin Posted on September 7, 2010 On April 20th, 1999, two students stormed Columbine High School and killed 12 students and a teacher while injuring 24 others before committing suicide. This is one of the worst school massacres in U.S. history. This entry was posted in KM24, September 7 Assignment and tagged columbine, massacre, school, violence. Bookmark the permalink.