MOUNT VERNON, Wash. -- Portions of a temporary Interstate 5 bridge could extend over the Skagit River in a day or two and the entire 160-foot gap could be filled next week, reopening freeway lanes that have been detoured since the May 23 bridge collapse, the Washington Department of Transportation said.
"We're gradually launching the bridge across the gap," spokesman Travis Phelps said Thursday.
The department expects to meet its goal of a mid-June reopening.
"We're making some good progress," he said.
National Transportation Safety Board investigators concluded their work at the scene, the agency said Wednesday. All of the bridge structure components of interest to investigators have been removed from the bottom of the river.
Some debris still has to be removed and divers have to make sure the bridge piers are in good shape to hold the temporary span, Phelps said. Some repairs also have to be made to the top of piers that will hold the replacement.
The temporary is actually two connected 24-foot wide spans being erected by the contractor, Acrow Bridges. The structure will be a total of 240 feet long for overlapping support, Phelps said. It will restore two highway lanes in each direction.
The section of the 58-year-old bridge between Mount Vernon and Burlington crumbled when a semi-truck with an oversize load hit an overhead girder. The truck made it off the bridge but two other vehicles fell into the water and three people were rescued with mostly minor injuries.
Traffic on the main highway between Seattle and Vancouver, British Columbia, has been detoured, causing congestion and delays. That section of the freeway carries an average of 71,000 vehicles a day. Washington State Patrol Trooper Sean O'Connell was killed while directing detoured traffic in Conway on May 31 when his motorcycle collided with a truck.
The Transportation Department is holding a public meeting Thursday night at Burlington City Hall to discuss traffic, the temporary span and a permanent replacement this fall.
The National Transportation Safety Board is still investigating and hopes to have a preliminary report on the facts and circumstances of the collapse by the end of June, spokesman Peter Knudson told the Skagit Valley Herald. A final report on the cause of the accident is months away.
Investigators finally interviewed the driver of the pilot car on Monday and examined a pole mounted on the front of her pickup truck. The pole is used to detect vertical obstructions in the path of the oversize truck.
The driver, Tammy DeTray of Olympia, said in a statement Wednesday that the pole did not touch the bridge. She would have warned the truck driver following her if it had, she said.
She was "horrified" to see the bridge collapse in her rear-view mirror, she said.
Investigators also have interviewed the driver of the oversize truck and victims of the collapse. The NTSB is still looking for another semi-truck that was on the bridge at the same time as the oversize truck.