A woman fighting for her life after a gas blast ripped through her home could have triggered the explosion by lighting a cigarette.

Fire investigators are probing the theory that Barbara Brown had been cleaning her cooker during the night and accidentally turned on the gas.

After going back to sleep, the 57-year-old widow is thought to have lit an early morning cigarette which ignited the build-up of gas causing the huge blast at 6.45am yesterday.

Mrs Brown is being treated in the intensive care unit at Pinderfields Hospital, where her condition was today described as critical.

Also injured in the explosion, which demolished two walls of the semi-detached and scattered debris across Bronte Old Road in Thornton, was Joan Collins.

Mrs Collins lived in the downstairs flat. She was taken to Bradford Royal Infirmary, but her injuries are not believed to be life-threatening.

Mrs Brown's daughter Melanie Milnes said her mother was a battler.

"She's been very poorly before and pulled through," said mother-of-two Mrs Milnes, of Thornton Road.

"I was called at 7am and told there had been an accident at my mum's flat."

The explosion was heard up to two miles away. Mrs Brown and Mrs Collins were dragged to safety by neighbours Adrian Woodward, Joseph Berry and Billy Brennan.

Transco workers and the firefighters checked the area and started an investigation into the cause, which was being continued by the Health and Safety Executive.

The damaged adjoining house is also due to be demolished today. The two Council tenants have been re-housed.

Mrs Milnes said: "I think my mum was doing some cleaning to show her independence - to show she can cope on her own. She must have somehow turned the cooker on and then later lit a cigarette.

"She has just got out of a residential home. She suffers from constriction of the airways, asthma and angina but she's a strong women."

Transco spokesman John O'Grady said: "There was nothing wrong with the pipeline system and we would like to calm the fears of people in the area."

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