I PARKED MY 2016 HONDA CIVIC IN MY GARAGE AND SET THE PARKING BRAKE. I EXITED THE VEHICLE AND WALKED INTO THE HOUSE. THE VEHICLE MUST HAVE ROLLED OUT OF THE GARAGE (GARAGE SURFACE IS RATHER FLAT, PROBABLY WHY I DIDN'T SEE THIS HAPPEN) DOWN MY SLOPED DRIVEWAY ENDED UP IN THE NEIGHBORS YARD. VEHICLE SUSTAINED DAMAGE TO THE EXHAUST, BUMPER, UNDERSIDE OF TRUNK AND RIGHT REAR TIRE. THANK GOODNESS THAT NOBODY WAS INJURED. AT THE TIME I THOUGHT MAYBE I MADE A MISTAKE BUT NOW THAT HONDA HAS ISSUED A RECALL ON THE PARKING BRAKE I UNDERSTAND WHAT REALLY HAPPENED. I DID SET THE PARKING BRAKE BUT IT APPEARS THAT IT DID NOT EVER SET. I HAVE SINCE SEEN THIS HAPPEN AGAIN WHEN I HAVE PARKED ON OTHER SOMEWHAT FLAT SURFACES AND RETURNED TO MY VEHICLE AND IT APPEARS AS THOUGH IT HAD MOVED A SMALL AMOUNT. WITH THE RELEASE OF DETAILS IN THE SAFETY RECALL (NHTSA CAMPAIGN NUMBER: 16V725000 ) I NOW UNDERSTAND MORE ABOUT WHAT HAPPENED.