WORKERS fled from a blazing Bolton factory -- just minutes before the roof caved in.

Fire swept through underwear factory Delux Hosiery late on Friday afternoon after welders accidentally set the roof alight.

Today the owner of the factory was reviewing the extent of the devastation which came just after a major refurbishment programme at the building.

Late last night the remains of the structure were declared unsafe and demolition work began.

A major rescue operation was launched when the blaze broke out because firefighters believed people were trapped in the burning building.

But all the workers escaped -- just minutes before the roof collapsed.

Roofers David Smith and Chris Sudden had been carrying out repair work on the roof of the High Street, Deane premises.

But it caught fire and within minutes the building was ablaze.

The two workmen scrambled down the scaffolding at the side of the building and alerted staff as the flames began to take hold.

The firm's six staff and Abarar Hussain, a journalist, were evacuated unharmed although one workman suffered smoke inhalation and was taken to hospital.

Luckily, many of the staff working for Bolton Information Centre, which shares the building, had left before the drama to take part in religious prayers.

By-standers watched in amazement as firefighters fought for more than two hours to tackle the blaze.

Eyewitness Mr Yacub Ibrahim, owner of Bridgeman News in Bridgeman Street near Derby Street, said he saw smoke and flames billowing out from the fire.

He said: "All the air went black and some of the residents nearby were running out of their houses.

"It was a very bad fire. All the cars had stopped and there were lots of people around watching. It was really busy."

Jet hoses streamed water on the building from an aerial ladder in a bid to damp down the flames.

Smoke could be seen for miles around and traffic was brought to a standstill as police blocked off the busy dual carriageway. Riaz Majid, the owner of the underwear factory which was making thermal knickers at the time of the fire, said he had only recently spent £40,000 on the building's renovation.

He heard about the blaze while he was travelling from the bank in his car.

He said: "I am devastated and shattered. I have lost everything, thousands of pounds of stock and the whole building.

"The workmen were just finishing off the roof after a huge renovation.

"The good thing is that everybody is unharmed. But all the hard work I have put into the building and the business over the past five years is gone."

Leading fireman Steve Bradley said the fire had been caused by a spark from a blow torch used by the workmen igniting dry timber.

He said: "The workers did the right thing in evacuating the building. They had a fire extinguisher and tried to put the fire out themselves but it took hold very quickly.

"They sensibly abandoned their attempts and left the rest of the job to us."

On-lookers watched as rubble fell onto the streets below as the roof caved in. Oxyacetylene canisters were also recovered from the scene.

Rubble from the roof piled up around the property and water poured from the front door and into the street.

Fire crews from Bolton, Farnworth and Atherton were at the scene and Station Officer of Bolton Central station Tim Greenwood said: "The fire flashed across the roof straight away. There was hardly any time at all before it just went up in flames."

One worker turned up for his night shift at 5pm to face the devastating news.

The worker, who did not want to be named, said: "I've been working here for two years. It was a great place to work. Very laid back without much pressure.

"It's a shame. The owner had only just finished work on the place. It had had new windows, been re-plastered inside and had a new roof.

"Now we are all going to have to find work somewhere else."