Freeway bridge collapses into Skagit River; no fatalities

By Mark Bowder, Columbian assistant metro editor

Published:

Updated: May 23, 2013, 10:27 PM

 
photoA truck is seen in the water Thursday after a portion of the Interstate 5 bridge collapsed into the Skagit River in Mount Vernon.

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photoA portion of the Interstate-5 bridge is submerged after it collapsed into the Skagit river dumping vehicles and people into the water in Mount Vernon on Thursday.

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photoThis photo shows the collapsed north end of the Skagit River bridge after it collapsed into the water.

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Skagit River Bridge

Authorities say there were no fatalities when the Interstate 5 bridge over the Skagit River near Mount Vernon collapsed Thursday evening, dumping vehicles and people into the water below.

The failure of a bridge with a similar design to the Interstate 5 Bridge over the Columbia River brought new attention to the issue of bridge safety as the Washington Legislature considers committing $450 million toward the Columbia River Crossing project.

“I presume its going to intensify the debate over the safety of the bridges. That’s been one of the principal issues with the bridges to begin with,” said Rep. Jim Moeller, D-Vancouver.

Moeller, who learned about the collapse when contacted by The Columbian for comment, said he hoped no one was hurt or killed in the collapse.

“I think it raises the question over the whole aspect of bridge safety — not only with this bridge, but also with the infrastructures of this state,” he said.

“It is extremely tragic and very unforeseen,” said Rhona Sen Hoss, a Vancouver resident and member of the group Washington for CRC, when contacted for comment. “That’s why we need to build a bridge. We need to advance the CRC, so that something like that will never, ever, happen to our citizens and families here in our region.”

Phone messages seeking comment from CRC critics Sen. Ann Rivers, R-La Center, Sen. Curtis P. King, R-Yakima, and Larry Patella of Vancouver were not immediately returned Thursday evening.

U.S. Sens. Maria Cantwell and Patty Murray both issued statements of support to those affected by the collapse.

The four-lane bridge over the Skagit River collapsed about 7 p.m. Marcus Deyerin, a spokesman for the Northwest Washington Incident Management team, said there were no fatalities or suspected fatalities. He said three people were rescued from the water and sent to area hospitals. He didn’t know the extent of their injuries.

The exact cause of the collapse has yet to be determined, but witnesses told a Seattle television station that a truck carrying an oversized load struck the superstructure of the bridge shortly before it collapsed. Photos distributed on social media show one section on the north end of the bridge detached from one of its concrete support piers. One end of the collapsed section appears to remain attached to its pier.

The Interstate 5 Skagit River bridge is of the same basic type — a steel truss bridge — as the Interstate 5 Bridge spans between Portland and Vancouver, and three of the four spans across the east and north forks of the Lewis River in the vicinity of Woodland.

Specifically, the Skagit bridge is a Warren through-truss bridge, the same as the Lewis River spans, according to the website bridgehunter.com It’s about 35 feet longer and eight feet wider than the northbound I-5 North Fork Lewis River bridges.

Unlike the Southwest Washington bridges, the Skagit River bridge carries both directions of Interstate 5, making it slightly busier than any of the local spans.

A 2010 inspection said the Skagit River Bridge’s superstructure was in fair condition and the deck and substructure was in satisfactory condition. The report concluded that its structural evaluation was “somewhat better than minimum adequacy to tolerate being left in place as is.”

The Skagit River bridge was given a sufficiency rating of 57.4 out of 100. By comparison, the southbound Interstate Bridge has a sufficiency rating of 49 out of 100 and the northbound has a rating of 18.5 out of 100 as of May 2011. Both spans of the Interstate Bridge, like the Skagit River Bridge, are rated as “functionally obsolete.”

Don Hamilton, an Oregon Department of Transportation spokesman, said that rating means the bridges need improvement to meet the demands being placed on them by current traffic loads. “Functionally obsolete does not mean it’s unsafe,” Hamilton said.

ODOT operates the I-5 Interstate bridge under an agreement with the state of Washington.

Hamilton said the twin spans of the Interstate Bridge were subjected to a week-long inspection last summer, and that a crew of nine maintenance workers are on the bridge every day.

“These are old bridges that require a lot of maintenance and inspection to keep them functioning safely,” Hamilton said.

Craig Brown of The Columbian and The Associated Press contributed to this report.

COMPARING THE BRIDGES

I-5 Skagit River Bridge

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Location: Skagit River, Skagit County.

Type: Warren through truss.

Built: 1955.

Length of longest span: 160.1 feet.

Total length: 1,111.9 feet.

Deck width: 56.1 feet.

Sufficiency rating (out of 100): 57.4.

Appraisal: Functionally obsolete.

Average daily traffic: 70,925.

I-5 Interstate Bridge northbound span

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Location: Columbia River, Clark/Multnomah counties.

Type: Vertical lift Parker through truss.

Built: 1917; rebuilt 1958

Length of longest span: 531 feet.

Total length: 3,538.2 feet.

Deck width: 38.1 feet.

Sufficiency rating (out of 100): 18.5.

Appraisal: Functionally obsolete.

Average daily traffic: 64,300.

I-5 Interstate Bridge southbound span

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Location: Columbia River, Clark/Multnomah counties.

Type: Vertical lift Parker through truss.

Built: 1958.

Length of longest span: 530.9 feet.

Total length: 3,538.2 feet.

Deck width: 40 feet.

Sufficiency rating (out of 100): 49.0.

Appraisal: Functionally obsolete.

Average daily traffic: 64,300.

Appraisal: Functional obsolescence is assessed by comparing the existing configuration of each bridge to current standards and demands, such as lane or shoulder width

Bridge sufficiency: The sufficiency rating formula is a method of evaluating a bridge’s sufficiency to remain in service, based on a combination of several factors. The sufficiency rating doesn’t necessarily indicate a bridge’s ability to carry traffic loads. It helps determine which bridges may need repair or replacement, not potential for collapse.

Sources: bridghunter.com; Oregon Department of Transportation; Washington State Dept. of Transportation