The fire was so big that flames could be seen shooting through the roof of the three-storey warehouse in Tuas.
Barrels and oil drums filled with flammable chemicals in the warehouse were being tossed around easily and they were sent flying by explosions that shook the warehouse's foundation.
And the combination of the wind changing direction and intense heat meant that Singapore Civil Defence Force (SCDF) firefighters had to move about to avoid being enveloped by the blaze.
But rumbling through the thick smoke was a weapon that helped them extinguish the inferno quickly - SCDF's new remote-controlled unmanned firefighting machine (UFM).
The fire broke out at a waste chemical facility at 23 Tuas Avenue 11 at 3.40pm yesterday.
Flammable chemicals, like petroleum-based products, were stored in oil drums and barrels in the facility.
As the fire devoured one container after another, it caused several explosions to erupt in the warehouse.
Leading 80 men to battle the blaze was SCDF Colonel Ling Young Ern, commander of the 4th SCDF Division.
Stationed at Bukit Batok, the 38-year-old and his men raced to the scene and saw flames shooting through the roof of the warehouse.
The fact the fire could do this even though the roof was three storeys high gave Col Ling and his team an idea of the task at hand.
Speaking to The New Paper last night in a phone interview, Col Ling said the heat was so intense they had to keep a safe distance of 10m while fighting the blaze.
The 13-year veteran of the SCDF, who is married with a son, nine, and a daughter, seven, said: "The fire was very intense and there were explosions going off now and then.
"There were metal drums and barrels scattered around, and they were flying around the warehouse. So we had to ensure our guys were safe."
Eight fire engines, two Red Rhinos, four supporting vehicles and an ambulance rushed to the scene.
Col Ling said one of his concerns was that the fire might spread to buildings nearby.
Using hand-held jets, the firefighters did their best to prevent the blaze from spreading.
But it was not the only thing they had to contend with. He said the wind direction kept changing and this meant the heat and smoke were being transferred to different parts of the warehouse.
Col Ling said: "The wind would spread heat along with it, so we had to protect the right area of the warehouse.
"We had to redeploy our guys to make sure they did not get into the midst of the smoke so they would not suffer from smoke inhalation."
But the blaze was still their main worry. Enter SCDF's robot firefighter, the UFM - a two-tonne machine that can go literally into the heat of battle to tackle the fiercest inferno.
It was unveiled on April 17 at the SCDF Workplan Seminar and received its baptism of fire yesterday.
Able to withstand temperatures up to 600 deg C, the Austria-made machine can fight fires using intense water mists, water jets and foam.
And yesterday, it proved its worth, to the delight of the SCDF. Able to lift objects up to 400kg and move obstacles its own weight, the UFM roared in.
Said Col Ling: "We could go into the centre of the fire and fight it more effectively. If we didn't have the UFM, we would have taken a much longer time and more men to fight it. We also would have to clear the obstacles ourselves."
Controlled by a joystick and linked by three hoses, the UFM blasted a powerful jet of foam to cover an area of 50m by 50m.
Col Ling recounted: "When it went in, we had the reach to fight (the fire) right in the heart of the factory."
After a 2½-hour battle, the fire was extinguished. No one was injured.
The UFM had done its job. Three more will arrive in July to strengthen the SCDF firefighting arsenal.
Said Col Ling: "We are definitely glad we have it. The UFM will take our firefighting capabilities to the next level."