Christmas is always an emotional time for Petra Nemcová.
The Czech model was 25 when, 13 years ago, she decided to spend the festive holiday in an idyllic resort in Khao Lak, Thailand, with Simon Atlee, her British photographer boyfriend of two years.
The pair spent December 25 playing football on the sand, watching White Christmas on television and choosing names for the children they planned.
But on Boxing Day, as the couple returned to their beach bungalow from a walk, they heard screams and saw people running. Suddenly the hut was destroyed by a monstrous wall of water.
Nemcová glimpsed Atlee, 33, screaming her name above the roaring tide as they were sucked out to sea. She never saw him again.
Months later he was confirmed to be among the 280,000 victims of one of the worst natural disasters in modern times. Nemcová survived but with appalling injuries.
"Boxing Day is always an emotional time for me," says Nemcová now.
"I always light a candle to remember all my loved ones who were impacted by that experience and the others who lost their lives. Every Christmas is very special for me, I still keep very strong connections with my adopted family in England, Simon's mum and her husband and daughter. Last year I spent the holidays with them; we're all very close."
Sitting in Claridge's in London, Nemcová looks like a gorgeous Mother Christmas in a red velvet mini-dress and beige thigh-high boots. Nemcová spent the previous evening here, at an Artists for Peace and Justice gala dinner raising money for Haitian communities.
Along with other celebrities including Elizabeth Hurley and Nicole Scherzinger, she served dinner to guests who included the Duchess of York. "The charity's motto is 'here to serve'," she explains.
Did she drop anything? "Thankfully not!"
Nemcová wasn't just there to waitress, but also to receive an award for her work running the Happy Hearts Fund, the charity she established after the tsunami, which rebuilds schools in countries hit by natural disasters.
So far it has opened 171 schools in 10 countries, allowing more than 100,000 children to return to school.
She's come a long way from her days as a Victoria's Secret model and Sports Illustrated cover girl.
Today, she says, "Twenty per cent of my life is fashion", the rest of the time she is travelling the world in the aftermath of disasters, such as the Nepal and Haiti earthquakes and the flooding earlier this year in Peru. Often she's accompanied by Atlee's friends and once - in Haiti - by Jodi, his sister.
Her inspiration for the fund came from the kindness she witnessed after the tsunami.
Having first clung to a roof, she found herself battered repeatedly by tree trunks, planks and glass in the water, shattering her pelvis in four places. She was then snatched by the second wave, but managed to grab the branch of a palm tree, watching in horror as other tourists and locals were swept away.
She stayed there for eight hours, drifting in and out of consciousness in the blazing sun.
Eventually, rescuers arrived, first a Thai man, who - discovering she was in too much pain to be carried on his back - found more Thais and some Swedish tourists to ferry her to land.
"They could have been swept away, something could have fallen on them, but they forgot themselves for others."
The hospital where she was taken was "like a war zone, so many injured people screaming in pain. There was no morphine - nothing, no beds. It was a very hard place to experience.
Nemcová's pelvis was so badly smashed near her spine that doctors declared it a miracle she wasn't paralysed; she had also lost half her blood from internal injuries.
She recuperated in the Czech Republic, but as soon as she could walk again she returned to Thailand, visiting shelters and temporary hospitals where, people told her, their greatest worry was not so much surviving the next few weeks, but how their communities would cope longer-term, after the aid agencies had departed.
"I realised if we could rebuild the school, we impact on not one but many families," she says. "No matter where you are, every family's life revolves around school and just knowing the school is open again gives communities a huge amount of strength and hope."
Recently, Happy Hearts merged with another charity, All Hands Volunteers, which supports disaster-relief volunteers, to create All Hands And Hearts, whose aim is to provide both immediate and long-term help to devastated communities.
As her life evolves, it can't be easy constantly having to revisit her old ordeal, but Nemcová does so stoically knowing its fundraising potential.
Since the tsunami, there have been various high-profile boyfriends including Sean Penn, James Blunt and Laurent Lamothe, former prime minister of Haiti. Now with Alejandro Grimaldi, a Miami-based businessman, she's clearly excited to be spending Christmas with him at their house in his home town.
"Just time in one place is such a treat," she beams. "Tragedy gives us the opportunity to put meaning into our lives," Nemcová says.
"It changes our values, gives us the opportunity to think where we want to go.
"I lost the person closest to me, but I got a second chance to live."