[Chin_Lee]

Numerous factors would dictate my actions in that situation. If I was with my family, my first priority would be their safety and getting them off that bus - even if it meant opening the window and lowering/throwing them off the bus. Which would then put me in the situation where if I was by myself. Then it really depends when I realize what is actually happening. IF I was sitting in the vicinity when Mr. Crazy started stabbing the poor victim, I would have intervened knowing that the victim would still have a good likelihood of surviving if my intervention stopped the continuation of bodily harm. However if I was a distance away from the incident and by the time I realized what was happening is beyond the point of no return, there is little sense or logic to try to disarm the suspect. At that point, you minimize the loss and isolate the danger (aka get the hell of that bus and keep the freak on the bus)
I feel so bad for the family of the victim - how do you ever prepare for something like this?