Not a good day for this driver (February 27). First was the stack displacement - not sure how that happened. Next was the trailer sliding off the fifth wheeel as he rounded a corner. The trailer brakes immediately stopped the trailer and the driver stopped the tractor soon enough to keep the trailer from dropping off the back wheels. He may have blown a tire valve, or it was just the last of the air bleeding out of the trailer, but there was a faint hiss for a few seconds.
The driver hopped out and cranked the landing gear down to the ground, but I did not stick around for the inevitable.