Gardai are investigating if ongoing roadworks played a part in the accident which claimed the lives of a father and his two children in Co Donegal.
John Mullan, aged 49, and his two children Tomas, 14 and Amelia, 6, perished on Thursday evening around 10.20pm when their family car crossed the road and slid down an embankment into Lough Foyle.
Mum Geraldine, 45, managed to escape from the sinking car and was rescued a short time later.
Now forensic investigators are beginning a painstaking investigation into what caused dad John to lose control of the vehicle at Three Trees in Quigley's Point.
One major aspect of their investigation is roadworks in the area on the R238 which were ongoing in the days prior to the tragedy.
It has been confirmed that the road where John lost control had been completely resurfaced just a couple of days beforehand.
It was also a wet and dark night when the tragedy occurred as the family returned from playing ten pin bowling in Derry.
Local people also claimed there was an extremely high tide that night and that waves were breaking over the embankment and out onto the road.
Road warnings about traffic repairs lined the side of the road where the accident happened.
It is also believed that some line markings along the road had not yet been completed before the accident occurred.
On Friday evening after the tragedy at approximately 6.15pm a line-marking truck arrived at the scene to carry out some work.
Garda Superintendent Eugene McGovern confirmed the road had just been resurfaced.
The Buncrana based Garda, who was at the scene of the tragedy just minutes after it happened on Thursday night, confirmed this will be one of many aspects considered by Garda forensic investigators.
He said "We still don't know what caused Mr Mullan to veer off the road but we will carry out a full investigation into all the circumstances.
"I was a wet and windy night and the stretch of road where the crash happened had recently been resurfaced so that will form part of our investigation."
It is understood that Gardai have yet to speak with Mrs Mullan about the moments before tragedy struck her family and changed all their lives forever.
However, her statement will give Gardai a vital insight into what happened and what forced her husband John to end up on the wrong side of the road before the family's black 2011 Mitsubishi ASX ended up in the deep waters of Lough Foyle.
Mrs Mullan, a nurse manager on the cancer ward at Letterkenny University Hospital, is originally from Galway.
She had worked through the entire Covid lockdown while John had been forced to take some time off as his garden centre near the family's home in Moville had been forced to close temporarily.
They had taken a few days off to be with their children before they returned to school in two weeks time.
Now Mrs Mullan is preparing to say a final farewell to her beloved husband and two children who will be buried following their funeral mass in Moville at 11am tomorrow (Mon).
