FIRE chiefs believe the huge blaze at York Minster Stoneyard was caused by an electrical fault.

A North Yorkshire Fire & Rescue Service spokesman said Wednesday’s fire was believed to have started accidentally because of an electrical wiring fault in one of the sockets in an office on the first floor of the building.

The blaze forced a race to save the Minster’s Great East Window.

More than 30 firefighters battled to douse flames that broke out in the office at the stoneyard, where experts had been working on the 600-year-old window in a £27 million restoration project.

Ian Tomlinson, of the York Glaziers’ Trust, helped firefighters rescue the glass and save the window, which was being stored in more than 300 pieces directly under where the blaze started.

The firefighters, together with Mr Tomlinson, the Rev Canon Glyn Webster and the Chamberlain, Dr Richard Shepherd, managed to prevent the delicate stained glass from being destroyed by the blaze.

The fire began shortly before 11.30pm on Wednesday and lasted until about 2am on Thursday. A North Yorkshire Fire & Rescue Service spokeswoman said: “The room where the fire started suffered 12 square metres of fire damage. The overall total fire, heat and smoke damage to the whole building was 400 square metres.”

The Dean of York, the Very Rev Keith Jones, also helped firefighters rescue the window, which is one of the largest areas of medieval stained glass in the world. It was built by glazier John Thornton between 1405 and 1408 and cost £58, paid by the then Bishop of Durham, Walter Skirlaw.

The Archbishop of York, Dr John Sentamu, visited the stoneyard to survey the damage caused by the fire.

He said after his visit: “I am glad to say that, apart from two offices that were damaged, fire officers worked at such great speed that the damage was limited – and no one was injured.”