Just a heads up we deal with knife attacks in Krav Maga and Karate.
http://www.cnn.com/2013/09/04/justice/texas-high-school-stabbings/index.html?hpt=hp_t2
Probably need to copy and paste.
The attached video is from John Whitman of Krav Maga Alliance. Please be advised we do not ever train with real knives!