11:29 AM: Thanks to the WSB readers who have pointed this out: On the other side of the continent, a concrete bridge spanning a river has been closed because of cracking, and there are warnings that it’s in risk of collapse. This bridge is even newer than the closed-since-March West Seattle Bridge. It’s the southbound span of the Roosevelt Bridge, a mile-long, state-owned bridge that carries U.S. Highway 1 across the St. Lucie River in Stuart, Florida [map], and this webpage suggests it has a lot in common with our bridge – it’s a concrete “box girder” bridge, for example. Local media there report some concrete has fallen but the nature and risk of the crack is still under investigation; they also report the bridge was last inspected two years ago, with no problems found. It was built in the mid-’90s. The cracked span is closed to traffic, so the separate northbound span is currently handling both directions. P.S. This bridge also, like ours, replaced a drawbridge, and had a somewhat tumultuous backstory.
5:49 PM: Now both sides/spans of the Florida bridge are closed TFN.
8:23 PM: A couple other datapoints we found – the Florida bridge has about half the over-water clearance of ours, 65 feet, and more volume – 120,000 vehicles a day.