SIR ROBERT McAlpine faces a huge compensation battle after one of its sites caught fire, causing King's Cross station in north London to be shut down.
East Coast Main Line trains were forced to stop at Peterborough after a blaze broke out on Monday morning on the eighth floor of an office block the firm is building at Goods Way, next to the station.
It was put out later that day.
Two acetylene gas cylinders were involved in the fire and fears of explosions caused a 200 m cordon to be thrown around the site of the blaze. Around 630 people were evacuated from the site and surrounding areas.
An HSE spokeswoman said: 'Who is responsible depends on how the fire started. At this stage it is too soon to know.'
The contractor was expecting to return to site yesterday (Wednesday) after the fire brigade's mandatory 48-hour cooling off period when gas cylinders are involved in a fire.
A McAlpine spokesman said on Tuesday: 'We cannot comment at the moment, as we are still not allowed on site.'
The firm is carrying out the work for developer Parabola Land.
The development will be the new London headquarters of Guardian Newspapers.