John Mullan, 49, and children Tomas, 14, and Amelia, six, from Moville, Co Donegal, died when their vehicle plunged off the road into Lough Foyle at Quigley’s Point as they returned from a family day-out last Thursday.
Geraldine Mullan, 45, the mother of the two children, survived the crash.
Hundreds of people gathered outside St Pius X parish church, Moville as their funeral took place on Monday.
Mrs Mullan told mourners how John took a rare day off from his popular garden centre business to spend with his family.
The four spent the day at a bowling alley, cinema and a restaurant before making the journey back home.
On the dark days in the weeks and months ahead that I have to endure, I know that I will get a sign and all three of you will be looking after me
Mrs Mullan recalled how they joked and laughed in the car with Tomas, telling them how he and Ameila were looking forward to going back to school.
“On the journey home, unfortunately, everything was against us that night. The high tide, the weather from Storm Ellen, the roadworks and slippery road conditions,” she told mourners.
“Anyone that knows John knows you couldn’t get a safer driver, so it wasn’t from speed or reckless driving, but I can picture it second by second, but I’m not going to recall the events as it’s not going to do anybody any good.
“It’s true what they say – in a second your life changes completely and on Thursday at half nine when we were supposed to be coming home and planning our next few days together, my life was irrevocably changed for the worst.
“When we landed in the water upside down and about 12 feet of water above us and the waves crashing, I knew my dear husband tried everything he could to get out.
“The injuries he sustained unfortunately pinned him in and he couldn’t get out. Everybody that knows my dear son Tomas was a good brother to his sister, he was the best big brother to the end because when they found them Ameila was in Tomas’s arms.
“On the dark days in the weeks and months ahead that I have to endure, I know that I will get a sign and all three of you will be looking after me.
“I was in the water and I think it was the best part of an hour but I had probably given up hope at that stage because I had screamed and roared and I called out their names until I knew all three of you had already gone.”
She described how the waves were crashing against her when local man Conor McDaid, who had spotted the car lights in the water and alerted emergency services, appeared to help the family.
“I know I asked you to let me go because I knew I had lost the three most important people in my life and I wanted to be with them,” she added.
“Every second, in every minute of every hour and every day that I am without John, Tomas and Amelia is a second too long.”
She thanked the emergency services for their help and for looking after her family on the night of the crash.
She said that while she was privileged to be the mother of Tomas and Amelia, she was sorry she could not be their mother for longer.
“They will be forever my darling babies,” she added.
“John, you are my rock, my soulmate, my best friend and you showed me what true love was all about.
“I had ten precious years with you. I thought I was going to grow old with you, but unfortunately Thursday night cut that time short.
“My heart is broken and it will never heal.”
Members of the Sea Scouts formed a guard of honour while nursing staff from Letterkenny University Hospital where Geraldine works and members from the local GAA team stood outside the church.
