The Florida Keys just had a double-fatality involving a trailer with unknown problems. From the photographs, I can't identify the towing vehicle, said to be too small. The rig involved is owned by the State, so you'd expect it would be subject to Federal inspection requirements.
In the link's slides below, the
boat is still headed in the original direction (north) after the towing SUV spun 180°. (Taking out the white van). The boat left the trailer and collided with still another car.
Traffic was closed for nearly five hours.
http://www.abc-7.com/Global/story.asp?S=12012165
Additional commentary:
http://keysnews.com/node/20961
And I just bought a boat trailer Sunday.