NHTSA Complaint #11044550 — 2018 CHEVROLET COLORADO

I HAD TRUCK STATIONARY PARKED ON A SLIGHT INCLINE ON A DIRT ROAD FOR ABOUT 5 MINUTES WHEN I HEARD A ODD SOUND LIKE "ARRRRR CLUNK" AND MY CAR ROLLED DOWN A HILL. I HAD MY CAR ON PARK WHILE ON 4LOW WITH THE ENGINE OFF. I DID NOT HAVE MY PARKING BRAKE ON THOUGH BUT THE INCLINE WAS SO SLIGHT I FEEL I DID NOT NEED IT. MY TRUCK WAS NOT LOADED WITH ANY EXTRA WEIGHT OR ANYTHING TO CAUSE IT TO ROLL DOWN THE HILL. I TRULY BELIEVE I AM NOT AT FAULT FOR THIS HAPPENING IT IS A BRAND NEW CAR HOW COULD THIS HAPPEN? PRIOR TO THIS I WAS NOT DOING ANYTHING EXTREME TO DAMAGE MY CAR IN ANY WAY. SOMETHING MUST HAVE FAILED ON MY TRUCK.