ARI SHAPIRO, HOST:
On this day 10 years ago, the I-35W bridge in Minneapolis was crowded with cars as rush hour was winding down. Just after 6 p.m. local time, the bridge suddenly collapsed and fell into the Mississippi River. Thirteen people were killed. One-hundred-forty-five were injured. The collapse put a spotlight on the nation's crumbling infrastructure, but a decade later, there are still tens of thousands of bridges nationwide that need to be fixed or replaced. NPR's David Schaper reports.
DAVID SCHAPER, BYLINE: Nancy Daubenberger is somber at this spot along the Mississippi River in downtown Minneapolis even as cars and trucks rumble and roar above her over the sleek, new interstate highway bridge she had a hand in designing. This is, after all, the spot where much of the twisted steel and crumpled concrete slabs landed when the former bridge collapsed 10 years ago.
NANCY DAUBENBERGER: That was devastating and tragic and shocking and a very, very sad situation.
SCHAPER: The 35W bridge had been classified as structurally deficient, meaning it was in need of extra maintenance and inspections. In fact, some repair work was going on when it fell. And the 40-year-old bridge was rated as fracture critical, meaning the failure of just one vital component could cause the whole bridge to collapse. And it did. The National Transportation Safety Board determined it was a design flaw that caused the 35W bridge to collapse. Gusset plates that hold the huge steel beams together were only half as thick as needed. The NTSB also found the weight of the nearly 300 tons of construction materials stockpiled on the bridge deck contributed to the collapse.
Daubenberger, a bridge engineer who is now director of engineering for MnDOT, says the state immediately inspected gusset plates on similar bridges statewide. And within months, the state raised the gas tax and funded a $2.5 billion 10-year bridge improvement program. The new 35W bridge opened just 14 months after the collapse, and Daubenberger says the state is on track to have all 172 other bridges identified as structurally deficient or fracture critical repaired or replaced by this time next year.
DAUBENBERGER: Certainly we've done a lot to ensure the safety of bridges so that it doesn't happen again.
SCHAPER: But what about bridges in the rest of the country?
RAY LAHOOD: America's infrastructure's like a Third World country.
SCHAPER: Ray LaHood was secretary of transportation in the Obama administration. He says more than 55,000 bridges nationwide are structurally deficient.
LAHOOD: Most states simply do not have the money to take care of - so they're patching them, and they're doing the best they can to keep them in a state of repair where people can drive over them. But it's a serious, serious problem.
SCHAPER: Federal funding for bridge and highway infrastructure has remained flat. While President Trump has pledged to spend up to a trillion dollars repairing and improving the nation's infrastructure, he still hasn't offered a detailed funding plan. So with federal revenue lagging in just the last four years, 26 states have followed Minnesota's lead, raising their own gas taxes to fund bridge improvements. And the number of structurally deficient bridges nationwide has dropped from nearly 74,000 10 years ago to fewer than 56,000 bridges today. But that's still nearly 10 percent of the nation's bridges.
Andy Herrmann is a bridge engineer and past president of the American Society of Civil Engineers. He says another crisis is looming as even safe bridges are getting older.
ANDY HERRMANN: They were built back in the '50s and the '60s with a 50-year design life. And we have to put the investment in to maintain them, to rehabilitate them, to reconstruct them when needed and to replace them.
SCHAPER: The good news, Herrmann says, is that advances in bridge design and construction techniques and in materials make new and rehabilitated bridges safer and longer-lasting. But he says if the Minneapolis bridge collapse was an infrastructure wake-up call, 10 years later, it's still not always being heard. David Schaper, NPR News.
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