The bridge's claim to fame is that it was built with a single 458 foot long steel arch to avoid putting any piers in the water to impede river navigation. The downside to that design, as one can now see, is that if any part of that single arch goes, the entire bridge is in the river. And I just saw a pre-collapse photo. The span right next to it has a huge support post in the middle of the river. That pretty much defeats the purpose of the single-span design, and the other bridge was there first.