SINGAPORE - It was six weeks into his freshman year as a business student at the National University of Singapore (NUS) in 2012 when he had the accident that would change his life.
Mr Alwyn Keng had turned up at one of the pools on campus to prepare for an inter-hall swim competition. Like so many times before, he jumped off the starting block and plunged into the pool.
But something went wrong this time.
"I sank to the bottom of the pool. I couldn't move and shout for help; I just had to hold my breath and pray for the best," said Mr Keng, now 27.
He has no explanation for what happened but is certain he did not hit the bottom of the pool after diving in.
An alert friend noticed he was underwater for too long, and dived in to pull an unconscious Mr Keng out.
When he came to on land, he realised he could not move any part of his body below his neck.
Mr Keng was rushed to a hospital by ambulance.
"Everything happened so quickly. I was in shock and didn't know what was happening; everyone was just rushing around," said Mr Keng, who recalled he did not hit the bottom of the pool when he jumped in.
At the hospital, doctors found that Mr Keng had somehow fractured his neck and shattered a bone during the "freak accident".
The injury affected his spinal cord, which impaired his movements.
But worse news was to come in the months during his recovery, said Mr Keng. He was told he was likely to be permanently disabled.
"I initially thought that I would be fine after they removed the bone fragments that were affecting the spinal cord, but when I used my phone to read up on my condition, I realised it's not as easy as that," he said.
While he regained some use of his hands and his upper body after several months of rehabilitation, he remains paralysed from his waist down - a condition that is likely to be permanent.
This realisation came as a huge blow to Mr Keng, an active student who represented his hall in swimming, handball and football.
"I was shocked, I remember feeling helpless and quite devastated. I used to do a lot of sports, so it felt like a huge part of my life had been taken away from me," said Mr Keng.
Since he was in primary school, he had been active in sports, often playing basketball or football during recess or after school.
In National Junior College, he was a member of the school's track and field team, as a discus thrower.
As he struggled through rehabilitation to recover as many body functions as possible, he started to doubt his ability to return to school to "lead a normal life" again.
"I was scared, I used to be quite confident and sporty, but after such a traumatic injury, my confidence took a hit. I was uncertain how people would view me," Mr Keng said.
"I think I had a bit of an inferiority complex, since I thought I couldn't be the person that I used to be."
But he had the support of the assistant dean of NUS Business School, Dr Helen Chai, who visited him frequently while he was in hospital to persuade him to return to school.
Dr Chai even arranged for him to drop by school to attend a lecture, just to get a feel of the school environment again, Mr Keng said.
It took a lot of convincing but in the end, he "gave in to her nagging" and decided to return to school.
In December 2013, after his discharge from hospital, Mr Keng resumed his studies.
To his surprise, he managed to do well in his first semester, scoring two As and a B for the three modules that he took.
It turned out to be the confidence booster he needed.
"It was evidence that I could achieve so much more, since I had already managed to recover to the extent that I could go back to school and do well in my academics," said Mr Keng.
He saw his studies as a way for him to have a "future to look forward to", in spite of his disability.
By then, he was able to get around school independently in a wheelchair, and had largely regained control of his upper body.
His father would also drive him to and from school; they live in a Housing Board flat in Choa Chu Kang.
He was determined to do well for the sake of his parents, who were nearing retirement age.
Both his parents are 55 years old now. His father works as a freelancer in advertising, while his mother works in a bank.
He has a younger brother, aged 26, who just graduated from the Singapore University of Social Sciences.
Over the next four years, Mr Keng slogged, often skipping sleep to catch up and prepare for classes.
In 2014, he received the Asia Pacific Breweries Foundation Scholarship for Persons with Disabilities, for his good results in school.
He later also joined the NUS Enablers club, a student interest group for special needs students, and became its vice-president.
Former hallmate Justinn Leong, 29, said he has seen Mr Keng mature in the years since his accident. It was Mr Leong who pulled Mr Keng from the pool in 2012.
"You expect the person to start thinking that the world has abandoned them and that they have no control over life, but on the contrary, Alwyn has always seemed to have control over his own life."
"He knows that he won't let his past stop him from achieving what he wants to achieve," said Mr Leong.
Mr Keng graduated with honours (highest distinction) from NUS last year, two years after his peers. He is now working as a bank analyst at HSBC.
Looking back, he credits his family and friends for creating a strong support system. Through it all, his friends and family never gave up hope on him, he said.
"I had to repay their faith in me," said Mr Keng.
He hopes his story can show that those with special needs are just as capable.
"All it takes is a bit of patience, and some special arrangements to level the playing field for them," said Mr Keng.
For example, in university, Mr Keng's teachers arranged for him to take his examinations on a computer. The bank, too, ensured that his working environment is a wheelchair-friendly one.
The biggest lesson he has learnt, which he hopes others will glean from, is to accept that everyone is different.
"Everyone runs their life at a different pace. There's no designated blueprint to say when and how we should live our lives.
"We shouldn't be afraid to be different. We just have to learn to accept it and move on."