Yeah, well, that was ... special. The bridge was built as a bunch of concrete cells without watertight doors between them. The contractor was installing watertight doors, which meant sawing holes in the concrete. They couldn't let the cut water into the lake due to environmental reasons. So it was stored in the cells, reducing the freeboard.

Then with most of the doors installed and open, a big storm blows up. Bridge is riding lower in the water due to the cut water. Water comes in and floods from cell to cell, and soon you've got a bunch of tugboats holding the surviving bridge from busting off its remaining anchor lines.

That wasn't a case of decaying infrastructure (other than it was a retrofit), that was a case of construction mishap, along with a side of "If you had meant to sink a bridge, I don't suppose you could do anything more to hurry it along other than drilling a hole in the bottom(1)".

(1) Which I've done/supervised, without the subsequent sinking of the bridge.