It was past midnight and they had just cut an aluminium sheet with a plasma-cutting machine.
One of the two workers left the work area to get a drink, while the machine operator continued with his work.
Using an overhead crane, he was preparing to hoist the aluminium sheet away from the machine.
But suddenly, the plasma-cutting machine - which uses electricity to superheat air into plasma (ionised gas) for cutting metal - exploded, sending debris into his face.
The incident last Saturday at Yan San Metals, a factory on Tuas Avenue 4, killed the 25-year-old Bangladeshi man.
According to its website, Yan San Metals is the only company in the Asia-Pacific region with the facilities to manufacture aluminium composite panels with a honeycomb core. They are strong and lightweight, and usually used in the marine and construction industries.
The police said they received a call at about 12.50am. When the Singapore Civil Defence Force (SCDF) arrived, paramedics found the worker unconscious.
He was taken to the National University Hospital, but died at about 4.40am.
The New Paper understands he suffered a punctured left eye and that his upper teeth were broken as a result of the explosion.
His right leg was also trapped under the machine.
His co-worker, also a Bangladeshi in his 20s, escaped unhurt.
An employee at Yan San Metals, who declined to be named, said the worker who was unhurt had been operating another machine before leaving the area.
The area they were working in is the size of about two security booths. TNP understands they were cutting products from a 6m by 2m aluminium sheet.
A Ministry of Manpower spokesman said its officers from the occupational safety and health inspectorate went to investigate the accident.
The company has been told to stop using the machine while investigations are ongoing, he said.
The police are also investigating.
Get The New Paper for more stories.