Some 80 people were evacuated from a waste-management facility in Jurong yesterday when a section of it caught fire.
No one was injured, but an acrid smell lingered in the air as smoke poured from NSL OilChem waste management's fixation facility in Tanjong Kling Road.
The fire, which involved flammable waste materials, was extinguished in two hours, said the Singapore Civil Defence Force (SCDF).
Furniture assembler Charles Goh, 45, who was making a delivery across the road at around 12pm, told The Straits Times: "There was thick smoke coming from the incident site and flames in the premises initially. I also heard a boom."
SCDF added that it was alerted to the fire at 12.15pm.
Firefighters "promptly surrounded and contained the fire, covering an area of 30m by 30m, with foam jets", it said.
ST understands that around 60 officers were deployed.
Responding to media queries, an NSL spokesman said: "The cause of the fire is unknown and we are doing all we can to assist the authorities with investigations."
She added that the fire broke out in the fixation facility, which treats industrial solid waste so that it becomes suitable as landfill.
This area occupies about 3 per cent of the plant complex.
Mr Lingeshwaran Nathan, 29, went to help SCDF officers when he saw "thick black smoke" coming from the site.
The health, safety and environment officer brought them water and helped them when they needed to remove their gear.
"I was going out for lunch but once I saw the smoke, I wanted to help in any way I could.
"It was quite a big fire," he said.
He told ST at the scene that around 20 workers from NSL OilChem were evacuated to the Natsteel building opposite.
Scenes of yesterday's fire were shared online. Pictures and a video posted on Facebook by user Chandra Prakas showed dense smoke rising from the building as a fire alarm sounded in the distance.
People were also heard shouting.
This is the second big fire in Tanjong Kling Road in two years.
In 2015, a woman was killed and seven others injured after an explosion in a lab, which also caused a fire.