Gardaí in Inishowen are appealing for information following last night's tragedy near Quigley's Point.
They say they were alerted to a car in the water at Three Trees, Quigleys Point, Donegal at approximately 10.20p.m.
The car had been travelling from Muff towards Quigley's Point when the driver lost control and the vehicle skidded across the road and down the embankment and plunged into the water.
The male driver aged 49 and two rear seat passengers, both children, a boy aged 14 and a girl aged 6 lost their lives. A 45 year old woman who was a front seat passenger managed to get out of the car and seek help.
She's been taken to Letterkenny University Hospital with non life threatening injuries. The bodies of the deceased have been brought to the hospital mortuary, where post mortems will take place.
Gardaí are appealing for anyone who was travelling on the road from Muff towards Quigley's Point between 10p.m. and 10.30p.m. last night, or anyone who was may have had sighting of a Black Mitsubishi ASX registration number, 11 DL 1566 in the area, particularly any road users with dash cam footage, to contact Buncrana Garda Station on (074) 9320540, the Garda Confidential Line 1800 666 111 or any Garda Station.
The road remains closed this morning as technical examinations continue.
Junior Minister Charlie McConalogue is a TD for the area.......