Click Image for Video of Bridge Collapsing
Updated at 7:48 PM, 8/2/2007
The focus has shifted from rescue to recovery today, but at roughly 3 P.M. Thursday afternoon the recovery operations were suspended due to high winds and swift currents as the U.S. Army Corp of Engineers proceeds to lower the water level of the Mississippi by 2 feet using the downriver Ford Dam. Water levels typically range between 4 and 13 feet in the section of river where the bridge fell. Divers were pulled from the water before they could extract an more victims, but Minneapolis Police Chief Tim Dolan said there are more bodies in the submerged vehicles.
Yesterday's numbers have been corrected. There are only 4 reported deaths, but there are 79 reported injured, and at least 20 people are missing. As previously mentioned, the death toll is expected to rise.
I went to Father Hennepin Park to see if I could catch a glimpse of the wreckage, and to talk to anyone who may have been there when it happened. I could see bits and pieces, and I talked to a few people who tried, unsuccessfully, to go help before they were shooed away by the police.
While I was there, I stumbled into a press conference. This is what I learned:
Tom Sorel, the Federal Highway Administrator, spoke and said the National Transportation Safety Board (NTSB) will help with an expedited design and construction as soon as possible (a.k.a. once the investigation is complete). The US Government has pledged reconstruction aide, and has already supplied $5 million for use in assisting with the traffic re-routing process.
Evidently, the I-35W bridge had noticeable cracks that had been documented as early as the 1990s, but they "were not populating." Nevertheless, the bridge had been labeled "structurally deficient." According to Sorel, the cracks were formed by 1960s welding techniques, but they were monitored over the years and were not growing.
Around the time recovery operations ceased, Governor Pawlenty promised immediate inspection of three similarly built bridges. The technical term for this type of bridge structure is the 1960s Arch-Deck Truss design - although, I'm not sure how to punctuate that. The bridges that are scheduled to be inspected will remain open while the inspection takes place until the "snooper trucks" arrive, at which point single lanes will be closed. Those bridges are located trunk highways 23, 120 & 123, and 243. All of these bridges are smaller, do not undergo the same traffic amount, but they are of the same structure type.
With this type of bridge, failure of one truss could precipitate the failure of all, according to Sorel.
Unlike what was previously reported, this bridge was not simply suspended above the water. Rather, it had a single pier of support in the water.
The most recent study by the URS confirmed that the bridge was "structurally deficient" and gave MnDOT two options:
- To use metal plates to strengthen/reinforce the bridge.
- To inspect the bridge with various safety tests.
MnDOT chose the latter on the grounds that drilling and doing work on the bridge could potentially damage it further.
"We thought we had done what we could," said Sorel. "Obviously, something went wrong."
This collapse has spurred many discussions about the failing infrastructure and about the Governor's recent dismissal of a transportation bill that would have included an incremental gas tax to the tune 10 cents per gallon in order to fund structural repairs Minnesota roads and bridges.
Despite this bill's dismissal, MnDOT former chief of staff Bob McFarland insists that there have not been any budget cuts or any inspector layoffs. Though he refuses to speculate about the reasons for the bridge's structural failure, he did say that deicing systems incorporated in the bridge's build are not being investigated as a concern or a factor in its collapse.
As always, more updates as they come.