Fiver Pin Separated From Hitch on Interstate

I have had a ball hitch tag trailer come off the ball when I neglected to lock it. We were traveling along at about 50 mph when we hit a railway crossing. It was quite rough as the truck crossed so I watched in the mirror to see how the trailer would bounce. I was visiting while hooking things up and neglected to latch the lock, hook up the safety chains or brake away cable. Anyway the trailer bounced off the ball and we were free. I just kept driving and told my wife we just lost the trailer back there. It took a bit before she realized I was serious. It probably skidded on the jack leg a quarter mile before going off into the ditch. I had to rewire the electrical plug but with the help of some passer bys we were able to lift it back on the ball and carry on. The only real damage done was to the jack.