This video is a great learning tool but rather graphic so be warned! Learns from this attack:
Be more aware of your surroundings when in possible threat locations:
Think of your positioning in the location and in relation to people in your vicinity
React quickly and decisively against the attacker (shock and awe)
Get control of the knife arm
If you can't get control of the knife arm due to being held deal with the leverage arm first (don't get task focused), then deal with the knife arm
If you can, get the hell out of there!!!!