A massive mudslide closed the highway south of the Canada-U.S. border in Bellingham, Washington, on Sunday.

The Washington State Department of Transportation announced the closure of I-5 near the Iowa Street exit at 5:45 a.m., saying emergency crews were called to the scene and all northbound lanes were blocked and southbound traffic was also affected.

As of 2 p.m., an estimated reopening time for the northbound lanes was not available.

Authorities said walls and barriers were damaged and a geotechnical assessment was needed.

WSDOT shared photos of the damage on social media, showing a tractor-trailer stuck in the mud.

“It’s going to take some time to clean everything up and make the necessary repairs. We have a lot of heavy machinery and personnel on site to clean up the debris,” the agency said around 10:30 a.m.

“Crews estimate approximately 2,000 cubic yards of debris spilled onto the lanes of I-5.”

A detour was in place, but WSDOT reported traffic was backed up for three miles, or about five kilometers. Drivers have been advised to use alternative routes or expect significant delays.