THE Botany Rd factory that caught fire this afternoon has been “completely destroyed” after intense heat caused the floor and roof to collapse.

Fire crews have been moved back from the Eastern Suburbs Shopfitters for safety reasons, as there are concerns about the building’s walls collapsing.

“Given the intensity of this fire, it has burnt with an enormous amount of heat, it’s put a lot of stress on this structure,” superintendent Ian Krimmer said.

“We are worried about the front wall and side wall.”

media_camera About 80 firefighters are on the scene of a fire at an outfitters at Botany. Picture: Daniel Aarons.

media_camera Members of the public run across the street as firefighters battle a large blaze at Botany.

Fire crews were using fixed monitors to put out the blaze as the collapsed roof and floor was preventing them from entering the building, he said.

The superintendent said this had made it a “very difficult operation, which had produced an enormous amount of smoke”.

The fire, which started around midday, was still in the process of being brought under control, Supt Krimmer said.

“It’s certainlty reduced it’s activitiy to a large extent compared to what it was earlier,” he said.

However Botany Rd remains closed as crews “still have a large amount of clean-up ahead”.

media_camera Heavy smoke greeted crews fighting the Botany blaze. Picture: Daniel Aarons.

media_camera While the outfitters has been destroyed crews worked to save adjoining buildings. Picture: Daniel Aarons.

The cause of the fire is yet to be determined, but it “has taken hold very quickly,” Supt Krimmer said.

“This particular factory has been totally destroyed by the fire,” he said.

Adjoining buildings, including the food warehouse at the rear, had been saved by fire crews.

All four workers who had been in the building when it caught fire had been evacuated safely, he said.

Crews were also managing nearby waterways to ensure no contamination.

media_camera Crews brought in a cherrypicker to battle the blaze which tore through the roof. Picture: Daniel Aarons media_camera Internal crews were removed as the building was deemed at risk of collapse. Picture: Daniel Aarons

media_camera Large amounts of smoke billowed out of the factory after it caught fire. Picture: Stephen Cooper

Tony Gorge, who works next door at a fire protection supplies company, said the alarm was raised just before 12.30pm after they could smell smoke.

The BP that was only two doors down carried mass amounts of fuel to supply trucks, he said.

“That’s a major service station, they’ve got a lot more than a normal station,” Mr Gorge said.

BOTANY | Multiple #FRNSW crews responding to a #fire in a shopfitter's premises, Botany Rd. Fire in the roof. F/fighting ops underway. — Fire & Rescue NSW (@FRNSW) November 30, 2015

Fire brigades were quick to arrive on the scene, he said.

Mr Gorge said workers from the shopfitters and his own workplace AFT Fire Supplies, had been evacuated.

However, the two shops shared a common roof and he was worried about fire damage to his own workplace, which had apparently already been flooded.

The Telegraph understands no one has been injured.

Botany Rd is closed in both directions between Edgehill Ave and Sir Joseph Banks Drive and motorists are advised to avoid the area. Foreshore Rd should be used as a diversion.