The link takes you to photos of a flipped trailer and a hitch that broke in half after the driver swerved to avoid a skunk in the road and then hit the brakes in the attempt to control her swaying trailer. The trailer was totaled and the two people in the tow rig are lucky to be alive.
Lindsey, the driver, has it right when she says she made an instinctual move to avoid the skunk and save her rig from the sway episode it caused, and that "sometimes your instincts are wrong."
Let's all learn something from this, OK?
* Never swerve hard to avoid hitting an animal in the road. Of course we all hate to kill something, but it basically comes down to the animal or you. You and your rig can survive running over something, but a dramatic swerve action will cause your trailer to make a dramatic swerve, too, and put you into a potentially lethal sway. What has to be in your mind is this: STAY STRAIGHT, STAY STRAIGHT, STAY STRAIGHT. Once you introduce a swerve, you can't take it back, and that instinctive turn of the steering wheel can kill you. (Imagine getting pulled off the road by an uncontrollable trailer while traveling between rock wall faces and this river.)
* In any situation when towing your trailer at speed, DO NOT HIT YOUR BRAKES. By braking the tow rig, you'll slow it down but not the trailer. Then the trailer will sway sideways, jackknife, and readily take over control of the forward momentum to pull your car or truck off the road. (Or, if you're luckier, detach from your tow vehicle from the centrifugal force.)
* Drive attentively, in general. Keep a frequent eye on your mirrors so you always know what's behind you and what might be attempting to pass your trailer. Look way out ahead, too, so you can anticipate moves before having to make them sudden. Stay way behind the vehicle in front of you, and always give yourself a long stopping distance so you can roll to a stop or slowdown instead of braking hard.
* Keep your speed down in the 55 mph range or lower. Vintage trailers weren't made to rocket down the road at today's freeway speeds--we didn't even have freeways when most of these trailers were made. You'll get to your destination soon enough, and the point is to get there in one piece.