TRUCK ROLLED DOWN A SLIGHT INCLINE 20-30 FEET WHILE IN PARK DRIVER NOT IN VEHICLE AND STRUCK ANOTHER CAR BEHIND IT. VEHICLE STATIONARY, IN FRONT OF 58 PARKER BLVD MONSEY NY 10952. DRIVER AND PASSENGER OF OTHER VEHICLE WITNESSED EVENT. VEHICLE WAS IN PARK AND OFF KEY OUT OF IGNITION OCCURRENCE 03/03/19 830-845 PM. TRUCK SUSTAINED BUMPER DAMAGE CAR SUSTAINED DAMAGE TO THE HOOD.