system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5:A movie bad guy gets his neck snapped in the movies by good guy and dies instantly. Yet people like Christopher Reeves break their neck and live for years. How do some people survive broken necks and others don't?

I appreciate there's a difference between a broken neck and a severed spine, but Reeves severed his spine and lived, while I think others can die instantly from a broken neck. This I don't understand.
gpt
A broken neck in and of itself is a totally survivable injury.

Broken bones in the neck, however, can put abnormal pressure on the spinal cord, causing damage leading to anything from numbness to paralysis to death. It's all about the extent of the damage to the spinal cord, not the bones themselves.

Incidentally, breaking the neck and severing the spinal cord is how execution by hanging works.