NTSB investigators on Saturday were at the scene of the bridge collapse on the Skagit River.
They have a boat in the water and at some point say they will likely send divers down to get a better look at the foundation of the bridge and some of the damaged parts.
Despite the holiday weekend, they will have investigators out for several days, although they're not sure how long the investigation could take.
Officials are looking for a temporary, pre-fabricated bridge to replace the 160-foot section that failed, Gov. Jay Inslee said. If one is found, it could be in place in weeks. If not, it could be months before a replacement can be built.
An average of 71,000 vehicles a day use the stretch of highway on the main route between Seattle and Vancouver, British Columbia.
Drivers are facing two, even three-hour delays because of bridge detours. But that headache is creating a huge boost for companies offering travelers other options.
Amtrak and BNSF are taking on more passengers. Alaska Airlines also announced a special fare of $99 each way, Seattle to Bellingham, through June 1. Some people are flying via Kenmore Air
Department of Transportation spokeswoman Kris Olsen said Friday they are working to get traffic running smoothly.
"We've been working really closely with the city of Mount Vernon to re-time signals, we've had our maintenance crews out here adjusting the detours," she said. "We're trying to find the right combination of what works for folks to keep traffic moving."
"We're never going to get it at free flow at this point, but hopefully we can at last get it moving at a pace that's reasonable."
Olsen suggested that people traveling in the area allow for extra time.
"The area is still open, you just need to plan for it," she said.
Northbound I-5 Detours
Use exit 227 and follow signs east to State Route 538/East College Way, turn left onto Riverside Drive then left onto George Hopper Road and back to I-5.
Use exit 226 and follow signs west to State Route 536/East Kincaid Street. Continue on SR 536, then turn right onto SR 20 and back to I-5.
Use exit 221 and follow signs east to State Route 534/Pioneer Highway to northbound SR 9. Next, turn left onto SR 538/East College Way and back to I-5.
Southbound I-5 Detours
Use exit 227 and follow signs east onto George Hopper Road. Next, head south on Riverside Drive/Burlington Boulevard, then turn right onto State Route 538/East College Way and back to I-5.
Use exit 230 and follow signs west to State Route 20/Avon Cutoff then south onto Avon Allen Road. From there, head east on State Route 536/Memorial Highway and back to I-5.
Anacortes Ferry Terminal Detour
Northbound I-5 Detour
Use exit 226 and follow signs west to State Route 536/East Kincaid Street. Continue on SR 536, then turn left onto SR 20 and follow signs to the Anacortes Ferry Terminal.
There are several ways you can keep updated on traffic through the area:
- Download the Seattle Traffic App for your mobile device
- Sign up for KING 5 Traffic Text Alerts
- Visit the KING 5 Traffic page
- Follow KING 5's Tracy Taylor @King5TracyT on Twitter
- Call 511
Amtrak adding one daily round trip north of Seattle
Amtrak says it plans to add one daily round trip between Seattle and Bellingham.
Amtrak, WSDOT, Sound Transit and BNSF Railway said they're working together to add the service. It would involve a morning departure from Seattle to Bellingham with an early evening return to help those who normally drive the route. Spokesmen said more details will be released as they become available.
Amtrak says its Amtrak Cascades service provides four trips each day over the Skagit River Rail Bridge, which remains fully functional.