The car moved into neutral. And because it was parked on a slight hill, it started rolling backward. "Just slowly at first, down this incline, toward a two-lane highway at the bottom," Hill said.

The car moved into neutral. And because it was parked on a slight hill, it started rolling backward. "Just slowly at first, down this incline, toward a two-lane highway at the bottom," Hill said. "And ...

Then the car started... As their car started rolling downhill, a stranger rushed in to help This story is part of the My Unsung Hero series, from the Hidden Brain team. It features stories of ...