Washington state bridge collapse sends cars into Skagit River (VIDEO)

A Canadian trucker driving the main route between Seattle and the Canadian border might have crashed into the Interstate 5 bridge over the Skagit River Thursday evening, causing it to collapse and send cars and people into the frigid water below.

Rescue crews were trying to free people from at least two vehicles, KING reported, and as of Friday morning, three people had been rescued and treated for minor injuries.

“We don’t think anyone else went into the water,” Marcus Deyerin, a spokesman for the Northwest Washington Incident Management Team, told The Canadian Press. “At this point we’re optimistic.”

William D. Scott, 41, was traveling with an oversized load when the crash happened, the Edmonton Journal reported.

According to the Journal, Scott's 18-wheeler was carrying heavy equipment to Vancouver, Wash. That load might have clipped a bridge girder, police said.

A representative for the company that hired Scott said he was unsure if any support vehicles accompanied the 18-wheeler to Washington.

Normally, those vehicles are equipped to test how much clearance is available and alert drivers to potential danger.

“We take this very very seriously,” said Ed Sherbinski, vice-president of Mullen Trucking. “We have a stellar safety record and all our resources are on this now.”

The equipment was said to be an oil-rig drilling piece. Sherbinski said the company received a permit from Washington state authorities that suggested the truck could safely navigate the bridge.

The bridge collapsed shortly after 7 p.m. local time between Burlington and Mount Vernon, Wash., a rural area about two hours north of Seattle, according to the Skagit Valley Herald.

The Washington State Patrol urged people to stay away from the area, although pictures posted to social media show crowds lining the river banks.

"I don't have much info. N/B and S/B lanes of I-5 Skagit River Bridge collapsed. People and cars in water. I'm very far away. Will update," Trooper Mark Francis tweeted.

According to The Associated Press, a sheriff's office rescue boat arrived shortly after the collapse and rescue crews were looking for people in the water.

One person could be seen sitting atop a vehicle in the water shortly after the collapse. At least one other vehicle was also reported to have fallen.

Built in 1955, the four-lane bridge is used by about 70,000 vehicles daily, according to 2010 figures reported by KIRO.

More than a quarter of the 7,840 bridges in Washington state are considered structurally deficient or functionally obsolete, according to the American Society of Civil Engineers' 2013 Infrastructure Report Card.