Part of the the A7 has collapsed in Longtown and it will be closed for the "foreseeable future".
This has happened near the bridge in the town across the River Esk.
The route is shut in both directions and people have been advised to find alternative routes out of the town.
A spokesman for Cumbria Constabulary said:
There has just been road collapse on the A7 in Longtown by the bridge, due to the state of the road over the bridge not being supported the road in both directions has been closed for the foreseeable future. Highways are attending to inspect the damage. Please find an alternative route out of Longtown.