Stopped in 80 Seconds: Armed Response, Not Gun Control, Halted School Rampage

But as reported in the Washington Times, the attacker's mission was stopped short by the quick response of an armed deputy sheriff who was working as a resource officer at the school.  Upon learning of the threat, the deputy ran from the cafeteria to the library, yelling for people to get down and identifying himself as a deputy sheriff.  The horrific incident lasted only a total of 80 seconds and ended with the shooter turning his gun on himself in the library as the deputy was closing in on him.  

http://www.nraila.org/news-issues/articles/2013/12/stopped-in-80-seconds-armed-response,-not-gun-control,-halted-school-rampage.aspx