komenalager: Bridge collapses in Washington state ? cars, people in water

শনিবার, ২৫ মে, ২০১৩

Bridge collapses in Washington state ? cars, people in water

Taylor Linden

Cars and people are in the Skagit River at the scene of an I-5 bridge collapse near Mt. Veron, Wash.

By Andrew Rafferty and Justin Kirschner, NBC News

Three people were rescued from a river after a bridge along Interstate-5 in Washington State collapsed on Thursday evening, plunging cars into the water below, according to Washington State Patrol.

MSNBC's Milissa Rehberger reports that people and cars were in the water after an I-5 bridge collapsed over the Skagit River in Washington state.

The extent of the injuries for the three is unclear, but all were evaluated on scene and were transported to area hospitals, according to Marcus Deyerin of the Washington Incident Management Team. Authorities say they have no reason to believe any others are still in the river.

Two vehicles were submerged in the Skagit River when the bridge fell around 7 p.m. local time (10 p.m. EDT), and traffic has been closed in both directions.

NBC Seattle affiliate KING5 reported that traffic was significantly backed up in both directions. I-5 is the main freeway that runs along the West Coast.

A witnesses told KING5 that an oversized truck hit the upper right side of the bridge before the collapse, though it wasn't clear if that caused the span to give way.

The minimum vertical clearance on the bridge (distance from the road to something a truck can bump into) is 14.5 feet. The standard height is 16 feet.

This I-5 bridge over the Skagit River at Mount Vernon was described by the Washington State Department of Transportation, after an inspection in August 2010, as "somewhat better than minimum adequacy to tolerate being left in place as is."

State inspection reports submitted to the Federal Highway Administration were reviewed by NBC News. That overall evaluation of the structural condition on the bridge corresponds to a score of 5 on a scale from 0 (worst) to 9 (best).

The bridge received identical scores on inspections in 2010, 2008 and 2006, and is on a schedule for inspection every 24 months, as generally required by federal regulations. State officials said Thursday evening they were working to make public a copy of the latest inspection report, presumably from 2012.

Looking at specific areas of the bridge, the substructure (piers, abutments, footings, piles, etc.) was described as in satisfactory condition, with the superstructure (beams, girders, stringers, trusses, cables, pins, hangers, etc.) in somewhat worse condition, listed as fair, according to the inspection data online from the Federal Highway Administration. "Fair" meant that all primary structural elements were sound but may have minor defects.

The 1,112-foot steel truss bridge was built in 1955, and was carrying an average daily traffic of 71,000 vehicles.

The bridge was of a "fracture critical" design, as are 18,000 bridges nationwide, meaning it could collapse if even one part failed.

Even after the bridge collapse that killed 13 people in Minneapolis in 2007, a haphazard system of inspections continued, with federal authorities choosing not to require re-inspection of all the fracture-critical bridges.

In a survey of every state by msnbc.com in 2008, only six states and the District of Columbia said they began to recheck all their fracture-critical bridges.

Officials in Washington state, like in most states, said they performed special inspections of only their few dozen bridges of the particular deck-truss design used in Minneapolis.

The bridge that fell Thursday did go on to receive its regular inspections in 2008 and 2010, according to the federal records, called the National Bridge Inventory.

Bill Dedman of NBC News contributed to this report.