Houston, with funding from DHS, has produced a video detailing how to better your chances to survive a mass shooter in the work place. Unfortunately the shooter in the video is laying waste to people with a pistol grip only shoutgun.
http://www.federalnewsradio.com/473/2966001/DHS-funded-video-gives-tips-to-survive-a-shooter
http://www.federalnewsradio.com/473/2966001/DHS-funded-video-gives-tips-to-survive-a-shooter