The unsolved murder of his girlfriend 25 years ago still haunts Mr James Soh.

Their romantic night out in East Coast Park on May 15, 1990 ended in a nightmare when they were stabbed by two assailants who have never been apprehended.

Miss Tan Ah Hong, 21, died from a deep stab wound in the neck, while Mr Soh, then 22, was knifed in the back.

To this day, Mr Soh told The Sunday Times, he is wary of footsteps behind him, and is always looking back and letting people walk ahead where he can see them. He also avoids secluded areas.

The case was never solved, and he is none the wiser as to why they were attacked.

"Until now it's still a big question mark for me: Why did it happen?" he said. "A life was taken; what they did was ridiculous, and I wish they could be found."

Now 47 and married, Mr Soh said he could not make out the faces of his masked assailants, but vividly recalled the attack and its aftermath.

He and Miss Tan had just started dating two days before, after years of friendship as classmates in secondary school, where they were both prefects.

"In school we were always together. She didn't play games or sports like I did but we clicked," said Mr Soh.

He was studying in a polytechnic when he finally asked her out almost a decade after they first met.

On that night, the couple were sitting on the spiral staircase going up to the second floor of the park's popular Amber Beacon tower and chatting. Mr Soh recalled seeing two men going upstairs. Suddenly they were attacked from behind.

"I defended myself instinctively," he recounted.

"I stood up when I was stabbed, and grabbed the guy. It was so fast, I only knew we were attacked, not that I had been stabbed. I got him over the rail and clinging on to the bar, but then he jumped down... he managed to run away."

Miss Tan, meanwhile, had run to the ground floor of the tower in an attempt to escape from the second attacker. By the time Mr Soh got to her, she was lying on the ground, in pain and with a wound to the back of her neck, but still trying to move. Their attackers had disappeared. "I tried to pull her up, but it wasn't easy, and nobody was around," said Mr Soh.

"Then I realised that my shirt was kind of wet, and it was blood."

Weak from the injury and the struggle, he could not pick Miss Tan up. Frantic, he spotted the only sign of life in the park's deserted corner - a restaurant called Singa Inn - and ran in that direction through the bushes to call for help.

Bursting through the front door, Mr Soh, who was covered in blood, managed to explain that Miss Tan needed help, before collapsing face down over a table.

He was taken to Singapore General Hospital, and he found out Miss Tan had died only two days later.

"I thought she had made it," he said. "There was regret that I never had a chance to get to know her better."

No weapon was recovered at the scene, and Mr Soh never saw the attackers' faces or heard their voices as the men had been careful not to speak.

No one was ever arrested though a report in The New Paper at the time quoted police sources as saying the attackers might have been foreign robbers.

He counts himself lucky that the knife missed his spinal cord, and he has tried to move past the attack.Mr Soh, who works in sales, said he told his only child, a 16-year-old boy, about the attack last year.

"I wish that anyone who has information or the culprits themselves could come forward.

"I always tell my son, 'You never know what can happen.' No matter how strong you are, my advice is think smart, don't go to places that let people have a chance to do something to you."