A 1,200-pound chunk of concrete tore off the underside of an overpass and rained down on motorists but caused no injuries, nearly a year after the deadly collapse of a Mississippi River bridge in neighboring Minneapolis.
The 6-ft x 9-ft section fell July 26 from the Maryland Avenue bridge onto two vehicles, choking traffic on I-35E for more than eight hours as crews inspected the overpass that shuttles nearly 140,000 motorists per day through downtown St. Paul.
The state Department of Transportation has deemed the 50-year-old bridge "structurally safe," said state bridge engineer Dan Dorgan.
The bridge was inspected last August. Officials knew the bridge deck was breaking down, but nothing suggested pieces would break off within the year, Dorgan said.
Deterioration of the concrete that caused the accident can be attributed partly to age, freeze-and-thaw cycles and road salt, he said.
"Certainly, it's an issue that concerns us, but the bridge is structurally safe," Dorgan said.
The bridge was built in 1958, remodeled in 1973 and given minor repairs in 1992. It is scheduled to be replaced in 2014.
There are no plans for a broad inspection of freeway overpasses. River bridges around the state got an intensive review after the August 1, 2007, collapse of the I-35W bridge in nearby Minneapolis, which killed 13 people.
