It is afternoon in the quiet but crowded library at Republic Polytechnic where she lectures, and Ms Kirsten Koh is weeping.
We are seated at a round table in the middle of the study area. Curious students at nearby tables nervously steal glances at us. But Ms Koh does not flinch. Her shoulders are squared, her posture upright, but she makes no attempt to hide her grief. Her tears fall, but she does not make a sound.
Next month, in the Sundown Marathon, the 32-year-old will attempt to walk all 42km. For a woman who once ran a marathon in 4hr 30min and completed an Olympic-distance triathlon in 2hr 50min, this does not seem a grand feat.
Till you notice her body, which is a crude painting of scars. It is a body so traumatised that she could not run for a year.
Her body's journey to recovery involved 19 operations totalling more than 80 hours, 5 litres of blood transfusions, 60 stitches, eight broken bones and 2 1/2 months of being bed-ridden.
Ms Koh's story began on May 19 last year. It is a night of which she has no memory. She relies instead on the Traffic Police report and the recollection of her Scottish housemate Orla Gilmore.
The close friends were cycling abreast along Mandai Avenue at about 9.30pm when Ms Koh simply disappeared.
Said Ms Gilmore, 33: "Suddenly, this lorry came up close to my front wheel, appearing beside me. The next thing that came to my head was: Where is Kirsten?
"Then I saw sparks coming out from the lorry's front wheel, which was probably her bike. The lorry had dragged her underneath."
And this is what came out: Bits and pieces of her bicycle. Her water bottle. A shoe. A pool of blood. And Ms Koh, lying in a crooked heap.
"I thought she was dead," said Ms Gilmore.
Ms Koh had fractured both her right and left ankles, and femurs. Her pelvis was shattered. Her left shoulder, fibula and shin bones were broken.
The doctors at Khoo Teck Puat Hospital told her parents - Jeff, a security officer, and Alice, a hotel housekeeper - to prepare for the worst.
So it began, the long, initially blurry road to recovery, through morphine and induced comas. Doctors mended her, but the battles that played out in her mind - denial, acceptance and then grief - were equally, if not more, trying.
Said Ms Koh, who lived to run but is now at a painful standstill: "I know it is a selfish thing to say, but at some points, I would rather have been dead.
"I was made into another person overnight. The hardest thing to accept was the fact that I was no longer able to do what I wanted to do. I was praying for someone to just kill me."
Her worst day was when the doctors asked her to try to move her legs - the same legs that had jumped through gymnastics routines in primary school, covered tennis courts in secondary school and survived hundreds of kilometres pounding the pavements of Tasmania, Australia, where she completed her degree.
She tried, she could not, and it crushed her. She became "sometimes unrecognisable".
Said Ms Gilmore, a diving instructor who met Ms Koh when she also worked at Republic Polytechnic: "In the first few weeks, she didn't cry at all. Then, it was almost like a dam breaking.
"Something small would set her off. Sometimes, it was the physical pain, or sometimes, it was friends who came to visit her - because she realised that they could come and chat, and when it was over, they could leave and she would be left behind."
Her pain, as Ms Koh now recalls with regret, had changed her: "I was very snappy, and I said very hurtful things to the people around me."
But Ms Gilmore, who has been the closest person to her throughout the ordeal, said: "I understood her. People were telling her how lucky she was to be alive. But this was a lack of understanding. I can't imagine a life like that, and those comments eventually got to her."
But Ms Koh endured. She started reading, and found heroes in books.
There was New York City firefighter Matthew Long, who in 2005 was hit by a bus and given a 1 per cent chance of survival. After five years, he was named among the world's 25 fittest men by Men's Fitness magazine.
There was Brian "Ironheart" Boyle, who at 18 "died" eight times as doctors tried to resuscitate him after his car was hit by a truck. He completed the 2007 Hawaii Ironman three years after leaving the Intensive Care Unit.
There were also letters, about 20 of them, that fuelled her. They were written by Ms Gilmore, who felt it was her responsibility to give her a full account of what had happened.
The first letter was a description of the accident. Others simply recorded events in the hospital, like who came to visit when Ms Koh was asleep or in a coma.
Maybe it was the inspiration that she gained through the written word, or maybe it was simply her will to run again. Either way, Ms Koh pushed herself right up till now, when she can stand upright.
She is 2cm shorter because of a broken left femur, which also causes a limp in her walk. But she is insistent on completing the entire 42km of the Sundown Marathon.
If she was knocked down while involved in sport, then sport is helping her to get up again.
Since getting up from her wheelchair in February, she has embarked on a seven-day weekly training programme. It includes swimming, weight training, stationary bike cycling and four days of walking.
She used to run the 9.8km from her home to the polytechnic, where she still lectures at the School of Sports, Health and Leisure. Now, she walks.
Ms Koh is a survivor. And it is a survival made possible by medicine, family, a close friend, her spirit - and one more thing: A helmet, which disintegrated on impact but did its job by protecting her head.
The remnants of that helmet - 15 pieces of blue and grey polycarbonate plastic - are kept in the storeroom of her HDB flat in Bukit Panjang.
It is a reminder of a dreadful night when her identity as an athlete was stolen. But it also symbolises a challenge to return to who she once was.
She said: "I don't want the accident to win. If I withdraw from sports, the accident wins."
The helmet, you see, cannot be whole again. But she can.
