Heavy rain, flooding and a rock slide have again closed a section of the major cross country highway Interstate 40 along its narrow corridor through the Great Smoky Mountains.

The slide and flood happened Wednesday afternoon around mile marker 450 in Tennessee, just to the west of the state line with North Carolina, the Tennessee Department of Transportation said on social media.

Traffic on I-40 East must exit at Hartford Road (Exit 447). Traffic on I-40 West must exit at Exit 20 before the Tennessee state line.

Drivers trying to get from Tennessee to North Carolina can take I-81 and I-26 to detour around the mudslide.

Other alterate routes involve North Carolina, Tennessee and Virginia highways, but drivers should use caution.

When will road reopen?

Crews continued to work Thursday to get the water and rock off the highway. Both lanes are close. They had not released when they think the road could be reopened, the DOT said.

The flooded section is part of 12 miles of I-40 in North Carolina and Tennessee that was washed away or heavily damaged by flooding that roared through the Pigeon River gorge during Hurricane Helene in late September.

Crews repaired and shored up enough of the old highway to open one narrow lane in each direction in March.

The lanes are separated by a curb several inches high that had to be removed to let vehicles stuck by the flooding and rockslide to turn around and go the other way.

About 2.5 to 3.5 inches of rain fell in the area over about three hours, according to the National Weather Service.

The permanent fix to stabilize what’s left of the road will involve driving long steel rods into bedrock below the road, filling them with grout and spraying concrete on the cliff face to hold them in place. It will take years.