AS POWER LIFTGATE WAS OPENING, I STARTED TO RETRIEVE ITEMS FROM BACK OF VEHICLE. ALL OF A SUDDEN, AS THE LIFTGATE REACHED THE TOP OF IT'S OPENING RANGE, IT IMMEDIATELY SLAMMED DOWN ABOUT 12 INCHES, HITTING ME IN THE HEAD AND CAUSING SEVERE NECK PAIN, AND CONTINUED TO TRAVEL DOWN. AT THIS POINT, I AM UNSURE WHAT THE ACTUAL DEFECT IS AS I HAVE NOT TAKEN THE VEHICLE TO GM YET TO BE DIAGNOSED. IN GOOGLING THIS ISSUE, I CAME ACROSS ANOTHER PERSON THAT HAD THE SAME THING HAPPEN. "I MADE A REPORT TO THE NHTSA. THE NUMBER IS 10464171" *TR