Trailors that are designed to haul heavy spot loads such as coiled metal are available. It’s not unusual for a driver or dispatcher to try to fit in some loaded money making miles and then with bad load balancing to have things go wrong. You can haul a lot of lumber on a trailor just fine. Put some metal coils on the same trailor in the wrong place and your going to have some failure issues. That savard load with the metal coiled in the pictures was loaded poorly for the trailor design without a doubt. Those two coils should have been spread with one on the front of the trailor and one on the rear of the trailor and probably been just fine. Apparently coils are one of the more dangerous loads to haul. Proper tie down with them is a bit of a process.