Comment by mc32

Not a civ engineer... But the way things cascaded and experienced a domino effect seems troubling. Contrast with the ‘89 SF quake caused one upper deck section of the then cantilevered section of the SF-OAK bridge to collapse. It fell into the lower deck, but did not cause the lower deck to give way. This seems to indicate they had better tolerances (higher safery factor). But that may be a very naive take.