THE bridge linking Seattle to Canada has collapsed, sending cars plunging into the river below.
Authorities said there were no deaths, and three people were rescued and taken to hospitals.
The four-lane Interstate 5 bridge – more than half a century old – collapsed last night, about halfway between Seattle and Vancouver, British Columbia, Trooper Mark Francis said.
Francis said he did not know what caused the collapse, which came at the start of one of the country's busiest holiday weekends.
The state transportation department said it was investigating whether an oversize truck load may have struck the bridge.
The collapse will raise questions about the nation's infrastructure, which has been a popular issue with President Barack Obama, who earlier this year warned against "raggedy" roads.
The American Society of Civil Engineers' 2013 infrastructure report card gave the country a dismal grade of D-plus overall.
Xavier Grospe, who lives near the river, said he could see three partially submerged cars, and the drivers were sitting either on top of the vehicles or on the edge of open windows.