An 18-year-old man has died following a crash on the Ballydugan Road outside Downpatrick.
Police said he was the driver of a car that was involved in a collision at about 22:30 BST on Tuesday. No other vehicle was involved.
The Ballydugan Road was closed between Bonecastle Road and Buckshead Road but has now reopened.
Police have appealed for information about the crash.