Once the trailer started to sway, this accident could have been avoided IF the driver had manually put on just the trailer brakes. This increases the tongue weight and makes it harder for the trailer to sway while slowing down.
A first responder account with more information:
“ This F350 single rear wheel truck was equipped with a Reese WDH with a sway bar, but he also had a rack on the back with a large generator, spare tire, firewood, and other camping gear on a Curt receiver hitch cargo rack.
The skid marks told the story, with evidence of multiple sway action as he entered a curve on the interstate, which in Idaho has a speed limit of 80 mph. The trailer overtook the truck, causing it to Jack knife, the trailer contacted the right Jersey barrier, and pushed the truck over the left Jersey barrier and over the side of the bridge. The trailer ball was pulled out of the hitch and the truck was dangling dangerously by only one remaining safety chain.”
Went from 6 attachments to 1. Looks like the slight curve that he entered “causing” this accident is over a 1/2 mile away. That’s a long way to the bridge fighting a sway. I agree the weight of the stuff on the back lessen the tongue weight but why use a WDH if you had very little tongue weight with a F350? In my first picture you can see the small friction sway ball is bent.