No one knows how the elderly man got on the MRT tracks near Expo station last Saturday.
Tragedy was averted when the driver of a train approaching Expo spotted the man, in his 70s, and managed to brake in time.
But question marks remain. How did the man get there? What was he doing?
The mystery deepened after the man's son told Chinese newspaper Lianhe Wanbao yesterday that his father, Mr Koh Chai Seng, did not have an ez-link card on him.
BADLY INJURED
There are also question marks over the extent of the elder Mr Koh's injuries.
A Singapore Civil Defence Force (SCDF) spokesman said Mr Koh had multiple injuries on his body and was taken unconscious to Changi General Hospital.
An SMRT statement on Saturday said the train driver had spotted a man lying close to the tracks between Tanah Merah and Expo stations, applied the emergency brakes immediately and stopped the train.
"The man, who was conscious, was duly moved to safety."
The statement added: "SMRT is working with the police and SCDF to investigate the matter."
A police spokesman said they received a call at 1.43pm on Saturday asking for assistance.
When they arrived, officers found a man "lying on the outer side of the tracks" near Expo MRT. He had head injuries.
The New Paper understands Mr Koh also suffered hip and wrist fractures.
He is still in intensive care and his condition is stable.
When TNP visited him last night, Mr Koh was hooked up to various tubes.
WHY WAS HE ON TRAIN TRACKS?
On Saturday, a cleaner at Expo station had spotted Mr Koh walking aimlessly on the platform.
A witness, who declined to be named, told Wanbao: "(The cleaner said) he would sometimes walk from the (platform) seats to the edge of the platform to take a look, before returning to the seat again."
The witness reportedly said that Mr Koh kept quiet when the cleaner tried to talk to him.
About 20 minutes later, when the cleaner returned to the platform, Mr Koh was already on the tracks.
It was unclear how he had managed to climb over the barriers.
TNP understands Mr Koh had walked for about three minutes on the tracks before the train arrived.
Commuters told Chinese newspaper Shin Min Daily News that the train stopped before it reached Expo station. The driver said a man was on the tracks.
A woman in her 40s told Shin Min: "The driver made an announcement asking passengers to remain calm. He said the train would be delayed by about 10 minutes."
Mr Koh's 47-year-old son told Wanbao the family was worried after his father left their Bedok home on Friday morning and did not return that night.
The family did not make a police report because they thought they had to wait 48 hours.
"Little did we expect the police to call us on (Saturday) afternoon," Mr Koh's son said.
He said his father has dementia and has gone missing on more than 10 occasions.
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