A woman has died after falling from a bus at Barnesmore Gap.
The tragedy occurred at 3.45pm yesterday.
Gardaí say a female passenger in her late 20s was seriously injured when she fell from the moving bus and was struck by a passing vehicle.
The injured woman was airlifted by helicopter to Beaumont Hospital, Dublin. She passed away some time later A post mortem will take place in due course.
The road remains closed as Garda Forensic Collision Investigators will conduct their examination of the scene this morning. Local diversions are in place.
Gardaí are appealing to anyone who may have witnessed the collision to come forward. Any road users who were travelling in the townland of Ardnawark, Barnesmore Gap, Donegal Town and who may have camera footage (including dash cam) is asked to make it available to Gardaí.
Anyone with any information is asked to contact Donegal Town Garda Station on (074) 9740190, the Garda Confidential Line on 1800 666 111, or any Garda station.