MOUNT VERNON, Wash. -- A truck carrying an oversize load struck a bridge on the major thoroughfare between Seattle and Canada, sending a section of the span and two vehicles into the Skagit River below, though all three occupants suffered only minor injuries.
It happened about 7 p.m. Thursday on the north part of the four-lane Interstate 5 bridge near Mount Vernon, about 60 miles north of Seattle, and disrupted travel in both directions.
Initially, it wasn't clear if the bridge just gave way on its own. But at an overnight news conference, Washington State Patrol Chief John Batiste blamed it on a tractor-trailer carrying a tall load that hit an upper part of the span.
"For reasons unknown at this point in time, the semi struck the overhead of the bridge causing the collapse," he said.
The Skagit County Sheriff's Department said three people - two men and one woman - were rescued from the water and transported to area hospitals. All three were reported in stable condition.
State authorities say there were no fatalities.
Witnesses reported seeing a semi-truck with an oversized load crossing the bridge and striking the beams on the north end before the bridge collapsed.
"I saw it. I was less than 50 feet away from the truck when it hit it," witness Dale Ogden told KING 5. "I had just passed it in the fast lane southbound and it had an oversized load. It was approximately 12 feet wide and over 14 feet tall. It was in the slow lane when I came by...I was behind the flag car and in front of the truck in the other lane and I saw the whip - normally tells you how high they can clear - start hitting the bridge. I looked in my rearview mirror knowing this was not going to turn out well."
The truck made it off the bridge and the driver remained at the scene and cooperated with investigators. The driver has been identified as a 42-year-old man from Alberta, Canada. He was driving for Mullen Trucking.
Two other vehicles went into the water about 25 feet below as the structure crumbled. Three people were rescued and were recovering Friday.
Helicopter footage showed several rescue boats at the bridge collapse scene with several ambulances waiting on the shore. One rescue boat left the scene with one person strapped into a stretcher.
A damaged red car and a damaged pickup truck were visible in the water, which appeared so shallow it barely reached the top of the car's hood. Crowds of people lined the river and watched the scene unfold.
Skagit County Sheriff Will Reichardt said rescue crews were nearby when they got the call.
"It was very fortunate that we literally had our boat operator on duty in the water in the area when the call came in. We were in the water within a few minutes," said Reichardt.
Dan Sligh and his wife were in their pickup on Interstate 5 heading to a camping trip when a bridge before them disappeared in a "big puff of dust.”
"I hit the brakes and we went off," Sligh told reporters from a hospital, adding he "saw the water approaching ... you hold on as tight as you can.”
Sligh, his wife and another man in a different vehicle were dumped into the chilly waters of the Skagit River.
Sligh and his wife were taken to Skagit Valley Hospital with non-life-threatening injuries. The other man was reported in stable condition at United General Hospital in Sedro-Woolley, hospital CEO Greg Reed said.
Sligh said his shoulder was dislocated in the drop into the water, and he found himself "belly deep in water in the truck." He said he popped his shoulder back in and called out to his wife, who he described as being in shock initially as they waited for rescuers to arrive in boats.
Alternate I-5 routes through Mount Vernon
The bridge collapse shut down I-5 completely, paralyzing traffic and prompting officials to detour drivers along alternate routes.
"We are going to be involved in a very vigorous effort to get the corridor north-sound again," said Governor Jay Inslee, who toured the damaged area late Thursday night. "We already started the process tonight of designing a system of detours to accommodate the time period it will take to replace this bridge...I have spoken to mayors of alternate routes that we hope to put into use."
Drivers were being diverted through alternate routes. Southbound traffic was being diverted to SR 20 while northbound traffic was being diverted to the East College Way Exit. Drivers are being asked to avoid the area altogether.
Bridge listed as 'functionally obsolete'
The bridge is not considered structurally deficient but is listed as being "functionally obsolete" - a category meaning that their design is outdated, such as having narrow shoulders or low clearance underneath, according to a database compiled by the Federal Highway Administration.
The bridge was built in 1955 and has a sufficiency rating of 57.4 out of 100, according to federal records. That is well below the statewide average rating of 80, according to an Associated Press analysis of federal data, but 759 bridges in the state have a lower sufficiency score.
According to a 2012 Skagit County Public Works Department, 42 of the county's 108 bridges that are 50 years or older. The document says eight of the bridges are more than 70 years old and two are over 80.
Washington state was given a C in the American Society of Civil Engineers' 2013 infrastructure report card and a C- when it came to the state's bridges. The group said more than a quarter of Washington's 7,840 bridges are considered structurally deficient of functionally obsolete.
Washington State Patrol is investigating the incident and is asking anyone who witnessed the truck hitting the bridge to contact them at 1-360-654-1204.