Can a high voltage line kill a person without touching it?
Yes. The higher the voltage, the larger an air gap is needed to keep it from jumping or arcing between conductors. You, a wet fleshy human, can provide an ideal path between two high voltage conductors if you get in the middle. You do not need to touch one. 

This is basically what allows lightning, Tesla  coils, and Jacob's Ladders to exist. 

As pointed out in the comments, the higher the voltage carried, the taller its transmission towers will be and the further each conductor will be from the others.