In an accident something has to give.
If the hitch didn't pull out of the frame, something else would have happened.
And my guess would be if none of the steel failed, the trailer would have rolled.
Still hard to imagine the dynamics of this incident given the alleged description from the owner.
Who knows, maybe it won't be long before traffic cam or dash cam footage shows up on the net.
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who's to say how the trailer brakes wear working if at all. I'm sure disc brakes would have made a big deference, perhaps the truck was trying to do most of the braking
Back to the alleged account by the driver, it seems as if there was little to no effort to stop. And perhaps hit the accelerator instead trying to get through quicker.
Either way with an apparent 2 second elapsed time, even properly working disc brakes are not going to stop in time to prevent running a light.
Add up driver time to gather data, process, reaction time, brake time, inherent delay with electric over hydraulic brakes and there is just not enough time.