I AM A REAL ESTATE AGENT. LAST YEAR 2019 I WENT TO AN OPEN HOUSE AND PARKED IN THE DRIVEWAY WHICH WAS ON AN INCLINE - WITH A PLATEAU FOR PARKING. I'VE BEEN DRIVING A STANDARD TRANSMISSION FOR 30 YEARS. WHEN I PARK I PLACE MY GEAR IN 1ST WITH THE PARKING BRAKE FULLY ENGAGED. I PARKED THE CAR, WENT INTO THE HOME TO VIEW THE HOME, AND WAS INSIDE 15 MINUTES. WHEN I WENT BACK TO MY CAR, IT WAS GONE. THE CAR HAD ROLLED BACKWARD DOWN THE HILL AND INTO A GUARDRAIL. THERE WERE NEIGHBORS ALL AROUND MY CAR, AND ONE MAN SAID, "IT MAKES NO SENSE IT THE PARKING BREAK IS ENGAGED." THE NEIGHBORS HAD VIDEO OF THE CRASH. THE CAR WAS PARKED APPROX 10 MINUTES BEFORE ROLLING DOWN THE HILL. MY CAR WAS DAMAGED BY THE GUARD RAIL, AND THANKFULLY NO HUMANS WERE HURT. HAD THE GUARDRAIL NOT BEEN THERE -- THE CAR WOULD HAVE GONE OVER A RAVINE AND INTO A HOME.