They were awoken by screams for help coming from above, but when his wife went to look out of the master bedroom window, she could not see anyone.
As the screaming continued, his wife ran into their younger son's room and was shocked to see their upstairs neighbour standing on their window ledge.
Businessman Cheong Wing Kiat, 58, told The New Paper over the phone yesterday that he ran into the room after his wife.
"He was holding onto the metal (window) grilles, and shouting, 'Fire! Fire!' He asked us to open the grilles," he said.
But when the couple tried to open the grilles to let their neighbour into their sixth-storey unit, they realised the grilles were locked. They could not remember where the key was.
The fire started on Saturday about 5.30am in the seventh-storey unit above the Cheong's in Hillview Green, a condominium at Hume Avenue in Bukit Timah.
Mr Cheong and his wife were alone at the time. Their two older children are studying overseas and their younger son, who is in the army, had been away in camp that night.
The family above was trapped as the fire raged in the living room and blocked their path to the front door.
Mr Cheong said their neighbour, Mr Timothy Ng, 29, had used a curtain to lower himself from the window of his home above to the 25cm-wide metal ledge outside their son's room.
"We were in a panic. Our windows were open, but we could open the grilles only with a key," he said.
"I tried to force them open, but I could not."
Fortunately, his wife quickly remembered that the key was in a drawer in the dining room, and rushed to retrieve it.
Mr Cheong said: "It was by a stroke of luck that we were able to find the key, and he (Mr Ng) was able to hold on to the grilles.
"I can't imagine if he had fallen. Falling from the sixth storey is no joke."
After they opened the grilles, Mr Ng climbed in, and Mr Cheong gave him a fire extinguisher.
Mr Cheong said: "He asked for a bucket of water to try to put out the fire, but I had guessed that the fire was very big, so I gave him a small fire extinguisher meant for kitchen fires."
Mr Cheong and his wife then called the police and the Singapore Civil Defence Force for help, while Mr Ng ran upstairs with the extinguisher.
The couple made their way down using the stairs with other residents.
Mr Cheong estimated the whole exchange lasted about three minutes, adding it "happened very quickly".
It is understood that the unit on fire housed 10 occupants: Mr Alvin Ng Swee Seng, 68, his wife, Madam Moreen Soh, 69, their two sons, Mr Terrence Ng, 41, and Mr Timothy Ng, their wives, two children and two maids.
Mr Ng told Chinese newspaper Shin Min Daily News he had clambered down from the blazing unit to Mr Cheong's unit below.
He then went back up to open the door from the outside and tried to put out the fire with the extinguisher. He also helped his parents out of the burning unit.
Singapore Civil Defence Force officers rescued the remaining occupants and put out the blaze using two water jets.
Nine people were taken to various hospitals.
Mr Alvin Ng, a retired businessman, and Madam Soh, a retired teacher, were taken to Singapore General Hospital with burn injuries.
Mr Alvin Ng died in hospital later that day.
Lianhe Wanbao reported on Sunday that Madam Soh was in a coma after suffering burns to 24 per cent of her body, including her face and ears.
Mr Cheong, who attended Mr Alvin Ng's wake yesterday afternoon, said: "It's sad what happened to Alvin. He was a really helpful and friendly man.
"Just last week, he came to my unit to retrieve a ball that had fallen into my unit for his granddaughter."
The Ng family declined to comment when approached at the wake yesterday evening.
Mr Cheong added: "Alvin's son was really courageous, I could see he was frightened and shocked, but all he wanted to do was save his parents."
This article was first published on May 3, 2016.
Get The New Paper for more stories.