The fire alarms were activated at about 1.25am and triggered the evacuation of 160 boarders from dormitories. Mr Edwards said the fire was contained in the science labs, where an overhead projector had been left.

“Fire investigations and police investigations suggest it was likely to have started with the overhead projector used last period,” Mr Edwards said.

“It had been sitting on the edge of a bench near a pile of textbooks and had been smouldering for many hours.

“It is likely to be a mechanical fault.”

Mr Edwards said the smouldering fire was put out quickly but it took longer to clear the smoke.

“We then needed to establish why the fire started and to eliminate any further risks before the staggered return of boarders back to their rooms,” he said.

Mr Edwards said the school had been well prepared to deal with the emergency.

“We’ve been doing fire related work here,” he said. “The smoke activated the alarms which woke the students and put in place a very pleasing evacuation. Only one student was affected by the smoke and was taken to hospital for observation.”

“People were very solidly asleep and we’re very thankful the fire alarms were there because the smoke was quite thick.

“There was a significant number of firemen here and a significant number of police and ambulance officers, and it was just wonderful to have so dedicated a group of emergency workers.”