>> everyone just seemed to panic and shock, like i was wondering what the heck was going on. >> joining me now are two witnesses to the stabbing rampage who got involved amid the chaos in different ways. steven mehta actually helped to chase down and tackle the suspect. cassie is a nursing student who rushed to help some of the victims. they join me now live from texas. it's amazing that both of you got involved, so many people run away from these kind of things. you really just went toward and did what you could. cassie, what was the first sign that something had gone wrong? >> well, i was in my nursing lab and i heard a scream from the hallway, thought people were just playing around, and went out to check and saw a girl bleeding out of her neck, running down the stairs. another one at the top. and i went to check and see if there was anyone else and that's when i saw the attacker stab another white male. outside of a classroom. >> so you actually saw that young man stab somebody? >> yes.