'IT is very hard to pick up a white coffin. It is harder to put it down. In the next couple of months we're probably going to have to lift Liam's coffin and put a coffin down for the second time."
There are millions of sad stories in the world. The story of Kerry family Tony and Mary Heffernan is perhaps one of the saddest, one of the most heartbreaking.
On January 18, 2011, their five-year-old daughter Saoirse died of an extremely rare, and incurable, neuro-degenerative condition called Batten's Disease. And on March 2, 2010, Saoirse's little brother Liam was diagnosed with Batten's Disease too.
The five-year-old has only months, if not weeks, to live.
Liam sits on his mother's lap at home in Castlemaine in Co Kerry last week. Blind and partially deaf, he is on heavy medication to make his young life even remotely bearable.
As a child he used to kick a football in the garden behind the house. Mary says that they thought Liam was going to line out one day in the green and gold of Kerry – "and bring home Sam".
"He's our champion," says Mary.
Mary adds she lies awake in bed at night thinking about the moment when Liam won't be here any longer.
"In a few more months, there is going to be nothing," she says. "It is not something I like to think about too much."
"You can't help it though," husband Tony, sitting on the couch beside her, says.
"We have to concentrate on now, to keep as positive as we can, and try to figure out when the real sadness comes, when the quiet times come," he says referring to the quiet that will come to their house on the Dingle Peninsula when Liam's heart is finally stilled, and there are no more cartoons on the telly.
The night before Liam's big sister died, Mary told Saoirse an extraordinary story. She said to Saoirse that she would be an angel in heaven but that she was lucky enough to go early and that mummy and daddy and Liam would follow her to heaven soon.
"I told it like I was telling Saoirse a story in a book," Mary says now. "She was clinging on to life. She was getting very agitated. She had a really tough couple of days. I just wanted her to know that it was okay for her to go."
Mary says that at that stage their prayers had changed from 'Please God save Saoirse' to 'Please God have mercy and take Saoirse'.
"It was horrendous what she went through the last three days of her life," Mary says.
"I suppose by telling her that it was to try to make it more peaceful inside her mind and that we would see each other again in heaven and it was okay to go. I would obviously rather if she didn't have to go and if she could have been well and stayed with us, but at that stage the time had come."
In 2010, Tony and Mary set up a charity, The Saoirse Foundation, to help and support families in the same situation as theirs and to make a positive life impact for sick children.
Through their project Bee Is For Batten's, they have an ambulance specially designed for sick children. Because Saoirse's favourite toy was a bee, they call the vehicle a BUMBLEance. To keep BUMBLEance on the road for a year, they need 35,000 texts.
"That will deliver sick kids up and down the county to hospital," says Tony, adding that you can also donate your old mobile phone.
Mary adds: "We've learnt with the charity that there are other people burying kids with different conditions other than Batten's. One of the things that our bereavement support at the charity does is that we keep them busy. They phone them. I'm hoping that they'll do the same for us, to get us through, because we will need help."
The anguish and heartbreak Tony and Mary have endured is unimaginable for any parent. Mary says she couldn't at this moment consider having another child. She says she would be too frightened that that child would suffer the same terrible fate as Saoirse and Liam.
"The answer is no," says Mary, clearly emotional.
"We couldn't have another child unless you would be guaranteed that they wouldn't have Batten's. It is something we have talked about. Would it be worth the chance? All I've ever wanted to be was a mother."
"When Saoirse passed, we still had Liam and Liam got us through – he is our little hero, so he is.
"The honest answer is that it is only in the last few months that we even contemplated that it might be an option, but we still haven't decided. It is just so difficult because I honestly could not watch another child go through this. I couldn't do it."
Despite their unimaginable heartbreak, the couple somehow manage to draw on the strength in each other to get them through.
"We have each other, which is priceless," Tony says, looking at Mary. "I love this lady beside me. I loved Mary before we had kids; our love got better because of the kids.
"We have a lot of sadness that will go on – we'll love each other after and enjoy every moment that we have together and do what we can to make a difference.
"There is no more you can do."
To help Tony and Mary raise funds for a Children's Ambulance Service simply text BUZZ to 50300 for a €4 donation.