PARKED THE VEHICLE DRIVEWAY, EXITED THE VEHICLE WITH KEYS IN HAND. WALKED BEHIND THE VEHICLE TO SPEAK TO NEIGHBOR, THE NEIGHBOR NOTICED CAR ROLLING, WE BOTH JUMP OUT OF WAY. VEHICLE ROLLS DOWN HILL ACROSS STREET ONTO NEIGHBOR PROPERTY AND FLIPS ON THE NEIGHBOR'S RETAINING WALL. IGNITION KEY WAS REMOVED FROM THE IGNITION SWITCH WITH THE VEHICLE IN THE DRIVE POSITION. *TR