He saw smoke coming from below the front door of his neighbour's flat and heard the elderly man inside moaning and gasping for breath. He rushed back to his unit one floor below to grab a hammer so he could break the padlock securing the front gate.
But his efforts were in vain.
Shortly after the fire was put out by firemen, a charred body, believed to be that of his neighbour, was found in the flat.
A fire broke out in the eighth-storey unit at Block 3, Telok Blangah Crescent, yesterday morning.
Mr Mohd Fahmi Shaik Maarof, 64, had just woken up and was playing a game on his mobile phone when he heard somebody banging loudly on a door nearby.
He did not pay much attention to the racket at first but became alarmed when it did not stop after about 15 minutes.
Speaking to The New Paper in Malay in his one-room rental flat on the seventh storey, the jobless man said: "Suddenly, I heard a loud crash coming from the flat directly above. It sounded like something had fallen on the floor. I was shocked."
Mr Mohd Fahmi ran up the flight of stairs to his neighbour's flat.
He said: "To my horror, I saw smoke coming out through a crack under the door. The smell was very strong.
"I could hear the old man inside groaning and gasping for breath. So I tried to open the door. "I banged on the door. Unfortunately, both the front door and gate were securely locked."
Mr Mohd Fahmi rushed home to get his hammer to try to break the padlock securing the gate.
But by the time he returned with the hammer, Singapore Civil Defence Force (SCDF) officers had arrived.
In a news release, the SCDF said it sent two fire engines and two ambulances after it was alerted about the incident at around 7.15am yesterday.
Its spokesman said the blaze was in the living room of the one-room flat and officers had to force open the front door to enter the unit. They put out the fire within five minutes with a water jet and found a burnt body in the living room.
Residents from the eighth to the 10th storeys were evacuated as a precautionary measure.
Two residents living several units away - a man in his 30s and a woman in her 80s - were taken conscious to the Singapore General Hospital for smoke inhalation.
The police said they are investigating the unnatural death.
TNP understands that the victim was Mr Teo Leng Soon, 77, who was known to be a hoarder.
When visitors dropped by, he would only open the door slightly as if he did not want them to see the mess inside.
Mr Ian Foo, centre manager of the Thye Hua Kwan Seniors Activity Centre at the void deck of the block of flats, said Mr Teo lived alone.
"Occasionally, he would come down to the centre and ask our staff to translate documents like bills and such for him," Mr Foo said. "My staff would visit him at his flat every now and then to check on him but he didn't really like to mix around.
"It's sad that this had to happen to him."
Odd-job labourer Lee Kok Hong , 59, who lives in the flat opposite Mr Teo's, said he was sitting near a staircase landing yesterday when a neighbour from the 10th storey alerted him about the smoke.
He said in Mandarin: "We banged on Mr Teo's front door but nobody opened it.
"I saw Mr Fahmi running upstairs not long after this. Then, the firemen came.
"It's sad. I last saw Mr Teo alive at around 9pm on Sunday."
SCDF said the cause of the fire is under investigation.