Washington State Bridge Collapse Highlights Infrastructure Needs Mike Siegel/The Seattle Times, via Associated Press More than 67,000 drivers cross the Skagit River every day along that stretch of Interstate 5 in Washington where a section of a bridge collapsed, according to the state. SEATTLE - The partial collapse on Thursday night of a heavily used river bridge on Interstate 5 north of Seattle caused no fatalities, but as the long holiday weekend began, it underscored the vulnerability of a transportation system that hinges not just on giant high-profile bridges and tunnels, but on tens of thousands of ordinary and unremarked components that travelers mostly take for granted. A bridge on Interstate 5 north of Seattle after the bridge collapsed Thursday night, sending two vehicles into the water. A section of the bridge, which crossed the Skagit River about an hour north of Seattle, crumpled around 7 p.m., apparently after being struck by an oversized truck, state officials said. Three people were injured, none of them seriously, when vehicles went into the river. But the ripple effects of the collapse could be huge - for commuters, freight haulers, neighborhoods around the bridge on detour routes and politicians in Olympia, Washington's capital, who have been loudly and publicly wrestling over the hundreds of millions of dollars in state money needed to replace another aging bridge over the Columbia River that separates Oregon and Washington further south on the Interstate 5 corridor. Interstate 5 is the main north-south route from British Columbia to southern California, transiting through both Seattle and Portland. Washington State's Department of Transportation has established detour routes through the cities of Burlington and Mt. Vernon, which are separated by the Skagit River, but urged travelers to avoid the area if they can. More than 67,000 drivers cross the Skagit every day along that stretch of the interstate, according to the state. The National Transportation Safety Board said investigators would be on the scene Friday to begin an investigation. "It shouldn't take an oversize load to let us know we have an oversized problem," said Gov. Jay Inslee of Washington in a telephone interview. Mr. Inslee, a Democrat, said that state transportation officials were scouring the country looking for a temporary bridge structure that might be brought in to span the river until the collapsed section can be fully replaced. Washington State faces a deadline this year to find money for the $3.2 billion project over the Columbia River, or risk losing up to $1.2 billion in federal funding. Oregon's legislature has approved $450 million, but Washington state's $450 million share has been stalled. About $1 billion would come from tolls.