Not nearly so dramatic but I lost a baby's highchair that was older than me, in a similar manner. Somehow it lifted straight up out of my little 4x4 utility trailer and flew away.
The sides of the trailer are plywood panels higher than this highchair and everything in there with it was large objects wedged tight. I hadn't imagined anything could happen. But I saw it in the mirror lift then fly out. There was some aerodynamic effect I hadn't anticipated.
Took the next offramp, found only splinters.
Sis was pissed. We both had used it as infants and I was taking it to her for her little granddaughter. Oops!