It’s understood the pedestrian was attempting to cross the road outside Black’s Centra shop in Letterkenny when she fell to the ground.
The 84-year-old suffered head injuries at the scene.
The woman was treated at the scene by ambulance staff who rushed to the area.
Gardai sealed off the road tonight and have begun an investigation.
It’s understood a motorist is being interviewed as part of that investigation as Gardai attempt to establish whether or not the lady was hit by the vehicle.
“The ambulance crew worked with the lady at the scene in an attempt to stem blood flowing from her head,” said one witness.
She was stablised and taken to hospital for further assessment.
The pensioner is said to be in a stable condition.
Gardai sealed off the road and there were long tailbacks as traffic was diverted from the scene on the Glenties Road.
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