HAZARD, Ky. (AP) — A section of the Mountain Parkway has closed indefinitely due to the collapse of the roadbed under the pavement, Kentucky transportation officials said.

The westbound lanes of the roadway were closed Wednesday at milepost 35.8 in Powell County, just west of the Wolfe County line, a statement from the Kentucky Transportation Cabinet said. Eastbound lanes weren’t affected.

A detour has been set up that has traffic getting off the parkway at Exit 40 in Wolfe County and using northbound Kentucky 15. Drivers can re-enter the parkway at Exit 33 in Slade.

Long-distance truck drivers might want to consider alternate routes west because the detour has a steep downhill grade with hairpin curves, the statement said. Possible alternatives suggested include U.S. 23 north to Interstate 64 at Catlettsburg or Kentucky 80 and the Hal Rogers Parkway west through Hazard to I-75 at London.

Engineers are evaluating the area to determine how to repair and reopen the highway, officials said.