Sometime between backing into my parking spot at work, then backing into a parking spot at the dentist, My Tailgate released/lowered. When I backed in at the dentist, my back up camera seemed to malfunction, so I just used my mirrors. Apparently, the camera was just pointing at the ground. Sine you can't see your tailgate in the mirrors; I could not see that it hit the retaining wall at the back of the space.