I researched a little as to whether snapping someone’s neck would actually kill them as quickly as it is often portrayed in the movies. The consensus seems to be that it’s possible, but it isn’t as easy and precise and immediate as Hollywood would have you believe.  It seems that the attacker would have to be exceptionally strong and would need to hit exactly the right spot, and even then, the victim wouldn’t die instantaneously. Of course, since we’re in a comic-book reality here, we can believe that VIXX really is that strong enough to do the deed.
Henchmen for Hire
a webcomic in a world of Superheroes and Supervillains by Jeff Langcaon
Snapping a few bones, even if it is in the upper spinal cord, doesn’t make one dead. Severing or severely damaging the upper spinal cord on the other hand results in paraplegia and stops diaphragm function; the victim loses all function below the head, including the ability to breathe.
That does kill the victim within 3-10 minutes. However, the victim looks dead immediately due to the total loss of motor, bowel and diaphragm function.
lack of oxygen to the brain also causes brain damage and or brain death after a certain period of time
Huh…unless there is a hospital right across the block; there are just a few problems:
1) The huge barrier preventing anyone leaving or coming in.
2) Zip is the speed star so getting him to a hospital on time will be harder… How fast can Mighty Man fly?
3) Vixx is standing right there.
But these are superheroes, presumably with stronger-than-average abilities. Might not their physicality be stronger than that of normal humans as well? Perhaps that might give Zip more time to survive his grievous injury.