SINGAPORE - Retired contractor Daniel Raj was at home in his eighth-floor unit in Block 538 Hougang Street 52 on Wednesday (Nov 24) when he heard "at least two blasts".
The 69-year-old said "one was very big - it sounded like a gas drum exploding", and from his flat, he could see a second-floor unit on fire in the adjacent Block 537.
"The fire was bursting out of the kitchen window, it was worse than the other side. I could hear what sounded like gas blowing out to feed the flames," he added.
The Singapore Civil Defence Force (SCDF) said on Facebook that it was alerted to the fire around 5.45pm. The blaze, which was eventually put out by firefighters, was linked to contents in the kitchen.
Five people - said to be family members from a seventh-floor unit - were taken to Singapore General Hospital and the National University Hospital for smoke inhalation.
No one else was hurt.
Retired technician Johari Sa'at, who lives next to the unit that caught fire, told The Straits Times on Thursday that "a lot of people live there... I see different young people, (I) don't know if they are renting or what".
Another second-floor resident, who wanted to be known only as Ms Xie, told Shin Min Daily News on Wednesday that five people were living in the flat and she noticed that they regularly received visitors.
The 45-year-old clerk said: "I had been worried that with so many people in the unit, clutter would build up - but little did I think something bad would actually happen."
Mr Johari, 68, who was shopping for groceries on Wednesday when the fire broke out, rushed home after receiving a call from his wife about the incident.
By the time he got back, she had "run downstairs already... I (went up to) turn off everything inside and I also went down".
About 20 residents from upper-floor units evacuated their homes before the SCDF arrived. Mr Johari said he saw two women receiving oxygen from paramedics on site.
On Thursday, when ST visited the block around 4.30pm, an acrid smell hung in the air. Soot could be seen on units up to two levels directly above the burnt flat.
The ceiling of a staircase landing outside the unit was also covered in soot.
Beneath that flat is a unit housing the Ang Mo Kio-Hougang Angsana Residents' Network. Maintenance staff could be seen scraping the ceiling and sweeping up debris from the floor.
When approached, an unidentified staff member declined comment, except to say that the work being done was unrelated to the fire.
Mr Darryl David, an MP for Ang Mo Kio GRC and chairman of Ang Mo Kio Town Council, told The Straits Times that "the common area has been cleaned up and we have made arrangements to repaint the affected ceiling".
He added that the damaged electrical cables and lights in the common area have been replaced.
"We will continue to render necessary assistance to the (people in the) affected unit and coordinate with other agencies where necessary," he said, adding that SCDF is investigating the cause of the fire.