A fire broke out at a US$2.4 billion (S$3.2 billion) petrochemical facility on Jurong Island around 3pm yesterday, causing a plume of smoke to stretch skyward from a burning oil tank containing about 20,000 barrels of light crude oil.

The smoke from the fire at a facility owned by the Jurong Aromatics Corporation (JAC) was visible even from the West Coast Highway on the mainland.

There were no casualties, but the fire raged on for five hours before it was put out by the Singapore Civil Defence Force (SCDF).

The heat was so intense that it caused the 40m-wide and 20m-tall tank to buckle in on itself, said the SCDF.

The fire was subdued only after firefighters surrounded the tank with machines that doused the flames with water and foam.

Smoke billowing from the fire at a facility on Jurong Island, as seen from Tuas South at 6.18pm. The burning tank was contained within a protective wall, so that two other nearby tanks would not be affected. ST PHOTO: SEAH KWANG PENG

They also had to deploy a "large foam monitor" capable of spraying 6,000 gallons of foam per minute.

"This operation was a race against time in view of the tank that buckled, and the need to prevent the intense fire from spreading to its immediate surroundings," said an SCDF spokesman. He said 150 personnel were involved in the operation and noted that the oil was not toxic.

The burning tank was contained within a protective wall. There were two other tanks at the facility and "fixed drencher systems" were activated to cool down these nearby tanks.

It is believed that a lightning strike could have sparked the fire.

The JAC is currently in receivership under restructuring firm Borrelli Walsh. A source at Borrelli Walsh said the amount of crude oil inside the tank was "only a small quantity" and the plant was "fully staffed" at the time of the incident.

The Straits Times understands that the staff were evacuated within minutes.

An in-house company emergency response team was also activated - a member of this team had to be sent to the National University Hospital for heat exhaustion.

"The fire was contained and it was just limited to that one particular tank; no other part of the facility was affected," the source said.

A security guard on duty at a shipyard just opposite the plant recalled the moment he saw flames erupting from the tank.

"We could feel the building shake a little when the fire broke out. I quickly told everyone to gather outside, just in case there were explosions," said Mr Muhammad Ali, 49.