So this just happened beside me...
Looks like the load was chained down ok. What is catching my eye is that it looks like the hitch failed and the trailer tongue is on the ground or close to it.
The hitch is more proof of the non working/ poorly adjusted trailer break theory. I try to remember to adjust mine each time I hook up. I know what each of trailers needs to be at empty. And for most loads I know where to set it. I always try to set it to where I just can feel them helping. If your trailer brakes lock up on a panic brake it can be as bad or worse than no trailer brakes. Having them set to where they will drag the whole rig down with the help of the truck brakes is very nice. When they are set correctly it is amazing how quickly you can stop heavy loads.
I find it interesting that only about 10k bent the trailer hitch on a sudden stop Like that. I thought it would have been good for more.