Minnesota bridge collapses into Mississippi River

Officials cautious in speculating cause of I-35W collapse

News Minneapolis-St.Paul Star Tribune, Chicago Tribune August 02, 2007
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At the scene of the collapsed I-35W bridge, which crumbled into the Mississippi River and onto roadways below during Minneapolis' Wednesday evening rush hour, authorities have lowered the number of confirmed deaths to four, but expect the number to fluctuate throughout the day, the Minneapolis–St. Paul Star Tribune reported. The number of injured rose to 79, according to doctors at Hennepin County Medical Center.

Efforts to recover bodies from vehicles trapped underwater resumed at about 10:45 a.m., according to the newspaper, after being temporarily halted because of safety concerns.

Heavy equipment to aid the work has been moved onto barges nearby, Stanek said. GPS systems and side-scan sonar will help divers and recovery workers determine the location of victims trapped in cars under about 7 ft of water. During rescue attempts Wednesday night, divers saw victims in submerged cars before darkness delayed the work, the newspaper reported.

Twenty to thirty people were still missing, and that many vehicles were still in the water, Police Chief Tim Dolan said at a news conference this morning. "The recovery involving those vehicles and the people who may be in those vehicles is going to take a long time," Dolan said. "We're dealing with the Mississippi River. We're dealing with currents, and we're going to have to do it slowly and safely."

Another potential hazard arose because a car that was under the bridge when it collapsed was carrying a potentially hazardous chemical, a type of polystyrene, said Fire Chief Jim Clack. It is possible that there are more hazardous materials at the scene, Clack said.

Officials have been cautious in their statements this morning, using words like "slow," "deliberate," and "careful" when answering questions about how inspectors responded to studies that described the bridge as having “fatigue cracks’ and being “structurally deficient.”

A former chairman of the National Transportation Safety board, James E. Burnett, said this morning he was intrigued by a 2001 University of Minnesota study that found signs of "fatigue cracking" in the bridge supports, though he noted that a later report apparently concluded that the bridge was in no immediate danger and was not in need of major repairs, the newspaper reported.

"I think that decision is going to come under new scrutiny," he said.

Regarding the label of “structurally deficient” in a 2005 federal study, Burnett said that "a structurally deficient bridge might be one not adequate for the traffic it takes, but not necessarily dangerous," the Star Tribune reported. "But a lot of structurally deficient bridges are dangerous."

Minnesota Gov. Tim Pawlenty said this morning that Minnesota Department of Transportation (MnDOT) engineers were aware of the reports and took them into account during inspections of the bridge in 2005 and 2006.

"While there were concerns about fatigue cracking, the engineers did not [determine] that dramatic action needed to be taken," Pawlenty said.

At mid-morning, the White House said an inspection two years ago found structural deficiencies in the bridge, according to the newspaper. White House Press Secretary Tony Snow said the 40-year-old, 1,907-ft-long span rated 50 on a scale of 120 for structural stability.

"This doesn't mean there was a risk of failure, but if an inspection report identifies deficiencies, the state is responsible for taking corrective actions," Snow said.

A 2001 MnDOT evaluation of the bridge did not signal any stress-related cracking in the bridge's deck truss, but did turn up several fatigue problems with the roadway connection leading to the bridge, the Chicago Tribune reported today.

President Bush offered his condolences to victims and said the federal government would help ensure that the span is rebuilt as quickly as possible.

"We in the federal government must respond, and respond robustly, to help the people there not only recover, but to make sure that lifeline of activity--that bridge--gets rebuilt as quickly as possible," Bush said in the Rose Garden following a Cabinet meeting.

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