OLYMPIA, Washington (Reuters) - A bridge collapse that sent cars and drivers tumbling off a four-lane interstate and into a frigid river in Washington state may have been caused when a semi-trailer truck crashed into the structure, officials said on Friday.
Three people were rescued from the Skagit River after a span of the bridge collapsed Thursday evening. Two of those rescued were hospitalized with hypothermia but no one was killed, officials said.
The collapse of the bridge, built in 1955, puts a spotlight on the dangers posed by the nation's aging infrastructure, and follows calls by engineers and some public officials to invest in infrastructure and upgrade bridges.
U.S. National Transportation Safety Board investigators were probing the cause of the bridge collapse on Interstate 5, the principal highway between Seattle and Vancouver, Canada. The bridge links the towns of Mount Vernon and Burlington.
Officials said the bridge, 55 miles (90 km) north of Seattle, was not among the spans listed by the state as "structurally deficient," which in some cases relates to bridges that cannot carry their intended traffic loads.
But the privately run National Bridge Inventory Database listed the bridge as "functionally obsolete," widely defined by public officials as a bridge not built to current standards and demands.
State Patrol Chief John Batiste said the bridge collapsed moments after a semi-trailer truck heading south struck the bridge's overhead truss. Investigators have talked to the driver, who officials said managed to safely cross the bridge before the span collapsed, and inspected the truck.
"The size of the load he was carrying appeared to create a problem, causing him to strike the bridge," Batiste said.
Local television images showed onlookers gathered on the bank of the Skagit River Thursday evening, watching the rescue operations under the fallen bridge section.
"The currents of the river are really rough. It's cold," Barbara Williams, who lives nearby, told Seattle station KOMO-TV.
In August 2007, a bridge fell into the Mississippi River in Minnesota, resulting in the deaths of 13 people and raising concerns about faulty infrastructure in the United States.
A 2013 report card from the American Society of Civil Engineers gave U.S. bridges a grade of C+, and ranked Washington state as having the 11th-highest projected cost of any state to perform what the organization deemed necessary repair or replacement of deficient highway bridges. The cost was pegged at $2.1 billion.
Washington state lawmakers are debating a proposed $8.4 billion transportation funding package championed by Governor Jay Inslee and fellow Democrats. A key point of contention has been whether to pay for a new Interstate 5 bridge over the Columbia River connecting Vancouver, Washington, and Portland, Oregon.
(Additional reporting by Laura L. Myers in Seattle and Nick Carey in Chicago, Writing by Alex Dobuzinskis; Editing by Cynthia Johnston, Scott Malone and John Stonestreet)