" Instant death is rare. It can be caused by the dislocation of the C2 from the vertebral body. When I see this it’s usually in hangings with long sudden drops such as from a bridge or a tall tree, and in motor vehicle and diving accidents when the victim suffers a hyperflexion injury after striking his head on a dashboard or the bottom of a pool. If the spinal cord is severed, the brain is no longer attached to the body. The heart and lungs instantly quit. "

― Patricia Cornwell , Flesh and Blood (Kay Scarpetta, #22)