There’s no reason for that bridge to have collapsed. I believe an overheight semi may have rammed the girders.
It appears that a truck did hit the bridge but that shouldn’t cause a collapse.
Over-sized loads must be permitted, and routed. If the truck was over-height, it should have been escorted. The truck in question made it past the north end of the bridge. I find it hard to believe that a single truck could take down that span.