Locals walking on the sandy beach which leads on to the large pier spoke in hushed tones of their shock and horror about what unfolded just after sunset on what was a beautiful spring evening.
Nicole Denby, who travelled from Londonderry with her two children, said she felt compelled to pay tribute.
"I didn't know the family at all but, I am a mum and I am just heartbroken," she said wiping away tears from behind her sunglasses.
"I just can't stop thinking about them."
Others hugged each other at the police cordon and gazed out over a calm Lough Swilly reflecting on yet one of the darkest days in history of the seaside resort.
One elderly woman from Buncrana said: "It was such a beautiful day, for something like this to happen - we just can't take it in.
"My heart goes out to the family."
Meanwhile, rescuers who had battled against time and the odds to try and save the stricken family also returned to the scene with heavy hearts.
Joe Joyce, from Lough Swilly RNLI, said some members were being offered counselling.
He recalled: "There were three people floating in the water. Each of the boats recovered a person from the water and commenced CPR and came back to shore and handed those casualties over to the emergency services.
"Once we located the car one of our members put on a snorkel and entered the water and recovered a further two bodies.
"There is just a numbness about what happened. Such a simple thing. It is very, very hard to take it all in. Whilst we train for this nothing can prepare you for what happened yesterday evening."