#1 You had a really crappy hitch to begin with. #2 You didn't have a pin to lock the hitch. #3 You didn't properly attach the trailer. One or more of those is true. The other fact is you didn't load your trailer properly. I had one come off once, and it had nothing to do with the hitch, it was my own stupidity. I didn't make sure it was properly attached. No way I could\can blame the hitch.