Driver Kulbir Singh was travelling along Tanah Merah Coast Road on Wednesday evening when he pulled over to help the driver of a tipper truck whose vehicle had broken down.
However, the 31-year-old good Samaritan was killed in a chain collision shortly after, pinned between the back of the tipper truck and another lorry in a four-vehicle pile-up.
The Straits Times understands that Mr Singh was standing behind the tipper truck when the driver of a lorry travelling on the same road lost control of his vehicle and hit a second lorry in front of him.
The collision caused the second lorry to hit yet another lorry before sending that vehicle crashing into Mr Singh and the back of the tipper truck.
In response to queries, the police said they were alerted to an accident involving a tipper truck and three lorries in Tanah Merah Coast Road towards Changi Coast Road at about 7pm on Wednesday.
Police said the 22-year-old driver of the lorry that triggered the chain collision was arrested for causing death by a negligent act.
He was trapped in the lorry after the crash and had to be rescued by Singapore Civil Defence Force officers using hydraulic tools.
He was conscious when taken to Changi General Hospital.
Another lorry driver, a 33-year-old man, was also taken to the hospital for his injuries.
Police investigations are ongoing.
Yesterday, friends of the victim said Mr Singh was the sort of person who would stop to help a stranger.
Mr Ranfathejeet Singh, who is currently in India, said that Mr Kulbir Singh was a friendly man who was religious and kind.
"He always smiled and gave me a hug when we met in the temple," said Mr Ranfathejeet Singh.
The two men had met at a Sikh temple in Silat Road four years ago.
Mr Ranfathejeet Singh had found out about Mr Kulbir Singh's accident through a WhatsApp group chat.
"I am very sad... Now, we cannot see each other any more," he said, adding that many of the friends in the chat group were "shocked" at the news.
Road safety experts said yesterday that drivers need to be especially careful when their vehicles break down on the road.
Mr Gerard Pereira, a training manager at the Singapore Safety Driving Centre, said: "Put your hazard lights on and put a vehicle breakdown sign about 20m behind the vehicle," he said.
"Try to get off the road because vehicles are coming towards you at a high speed and, sometimes, they can't see you until it is too late."
He also cautioned that people should not stand behind the broken-down vehicle.
If they are with someone else, one person should keep an eye on oncoming vehicles and wave something luminous to alert them.
There have been previous accidents involving good Samaritans who had stopped to assist others. Last July, two people were killed in Johor Baru when a car rammed into them as they were trying to assist two victims of an earlier crash.
• Additional reporting by Aw Cheng Wei and Felicia Choo
