A fire suppression system that could have saved Glasgow School of Art was “agonisingly close” to being activated before the building was devastated.

The Sunday Times reported that pumps needed to complete the installation arrived on site the day before fire engulfed the landmark Charles Rennie Mackintosh masterpiece.

At the height of the inferno, 120 firefighters battled to save the building which was nearing the end of a multi-million restoration after a fire in 2014.

READ MORE: Revealed: the missing safety checks at ravaged Glasgow School of Art fire

The mist fire suppression system was to have been been installed but the pumps were among the last components needed.

Keith MacGillivray, chief executive of the British Automatic Fire Sprinkler Association, said: “The pumps were delivered on Thursday, the day before the fire.

“Each one was in ten pieces and would have had to have been assembled on site, but the system was agonisingly close to being operational.”

The cause of the fire is being investigated by Police Scotland, the Scottish Fire and Rescue Service and the Health and Safety Executive.

READ MORE: Glasgow School of Art fire was like 'battling a volcano' say firefighters

It is understood that interior wood furnishings were being coated with linseed oil, a highly flammable substance, fuelling speculation over whether or not strict safety precautions — such as limiting the amount of flammable liquids on site and disposing of waste, such as oil-soaked rags, in metal skips — were observed.

David Mundell, the Scottish secretary, said: “It’s a scene of devastation, utterly shocking to behold.”

Muriel Gray, chairwoman of the GSA board, believes that the building can be restored but the walls have moved as much as six inches in some places as a result of the fire, raising fears it could collapse without warning.

The tragedy raises questions about why, more than five years after it was due to be fitted, a fire suppression system was still not operational in the grade A-listed building.