Travel in and out of much of Western North Carolina is nearly impossible after heavy rains and flooding battered the state in the path of Hurricane Helene.

The department said that any civilian car on the road would hinder emergency responses. More than 400 roads were affected by the closure alert, including two major arteries for the region: Interstate 40 and Interstate 26, which Mr. Moody said were too damaged for cars to pass.

Road closures caused by surging rivers and disrupted communications in the wake of Hurricane Helene on Saturday isolated western North Carolina in what officials are calling a "catastrophic natural disaster.