DRIVER PARKED VAN ON A HILL, PUT THE VAN IN PARK AND EXITED THE VAN. WAS OUT OF THE VAN FOR APPROXIMATELY 15-20 SECONDS. DRIVER HEARD A POP AND A GRIND. TURNED AND WATCHED HIS VAN ROLL DOWN A HILL INTO A HOUSE. INCIDENT WAS ON A CITY STREET IN A NEIGHBORHOOD. VEHICLE WAS STATIONARY.*DT *TR