A portion is of Interstate 40 near the Tennessee-North Carolina state lines is shut down because of a mudslide. A Tennessee transportation spokeswoman says it isn't yet clear how long the lanes will remain closed. Mud and rocks tumbled onto the highway early Tuesday in Cocke County. Tennessee Department of Transportation spokeswoman B.J. Doughty said another house-sized boulder was in a precarious position above the highway and TDOT geotechnical personnel were checking how stable the situation was. Doughty said the department was preparing to let an emergency contract to remove the debris and was working with North Carolina authorities on a detour. Westbound traffic was initially being routed onto Interstates 26 and 81 - a long detour through the Tri-Cities. A rockslide in October 2009 shut down all lanes of I-40 in both directions for several months.