Report: Design Flaw Caused Bridge Collapse
A report due out today from the National Transportation Safety Board cites a design flaw from 1965 as the chief culprit behind a deadly bridge collapse in Minneapolis last year that killed 13 people and injured 145.
NTSB investigators found that the Minneapolis Interstate Bridge, also known as the Interstate 35W bridge, dropped 108 feet into the Mississippi River on Aug. 1, 2007, because of problems with poster-sized "gusset plates."
The plates, which held the bridge's steel beams together, were only half the required thickness. Other problems identified included the additional construction materials that were stockpiled on the bridge's center, bringing the total weight in that stretch to 287 tons (equivalent to the weight of a 747 airplane), The Associated Press reported.
During a two-day hearing on the safety board's findings, new eyewitness testimony was also released. Many of the stranded motorists reported "hearing loud pops, then the smell of concrete dust as the bridge dropped, then seemed to pause and then plummet," according to the Chicago Tribune.
Still, the report's findings left some unconvinced.
Erica Gwillim and other survivors told the Minneapolis Star-Tribune that they were hesitant to accept the safety board's findings at face value. "I feel like this is going to continue to be something that I don't have answers to," Gwillim told the paper. "Somehow I just have to be OK with that."
Others pointed to the extra construction materials as the potential chief problem.
"I could have figured that out," said Valerie Redanz of Falmouth, Mass., who lost Julia Blackhawk, the mother of her two grandsons, in the collapse. "If I have something in my house here that's wobbly or shaky or in bad repair, I don't go piling things on top of that. Do we need an expert to tell us that?"
The board's engineers said the bridge may have had cracks in its welds and rust in places, but said such problems "had nothing to do with the collapse," The New York Times' Matthew L. Wald notes.
In lawsuits served Wednesday, bridge victims and their survivors also alleged that a consulting firm didn't properly inspect and evaluate the 40-year-old bridge and failed to convey the span's "dire condition" to the Minnesota Department of Transportation.
Please email us to report offensive comments.
Posted by: Whys | November 14, 2008 1:41 PM
Posted by: SoCal_Mark | November 14, 2008 10:15 PM
Posted by: dumbanalysts | November 15, 2008 10:45 AM