A blaze that destroyed a flat may have been started by this week’s heatwave.

Firefighters believe that bright sunlight refracted through a window may have set light to soft furnishings at the first-floor flat in Westerleigh Road, Chippenham, at 2.50pm on Monday passing through glass may well have started the inferno, which spread quickly, and resulted in two other flats also being damaged.

Investigations into the fire, which took hold as parents returned from the school run with their children, are continuing, but group manager Ian Rennie, based at the fire HQ in Devizes, said it could have been caused as the result of a freak accident.

“There is a distinct possibility that the weather could have caused this, very much so,” he said.

“We’re having some unusual weather at the moment, and it could be that the angle of the sun combined with the lack of leaves on the trees at this time of year may have caused a situation where light was intensified through a prism and caused a fire.”

He said the blaze had started incredibly quickly. “Considering that the fire station in Chippenham is not far away, the flat was fully on fire by the time they arrived minutes after getting the call,” he said.

“The first call to us was from a neighbour saying there was white smoke coming from under the eaves, and minutes later we were called again to say the whole roof was on fire.”

More than 30 firefighters from Chippenham, Corsham, Calne, Melksham and Swindon tackled the blaze.

Firefighters Russ Looms and Charlie Afele, based at Chippenham, went into the flat looking for the couple believing they were in there but were called out before the roof collapsed.

Watch manager Paul Hanlon said: “We’re not sure how long that flat had been on fire before we arrived but it was fairly well-developed.

“Two firefighters did go in to the building because we’d heard from neighbours that the owners may have still been inside, but fortunately no one was injured.”

Station manager Antony Bholah said: “I’d like to thank the local authority and the British Red Cross for their help – they were brilliant.”

Maureen Lloyd, chairman of flat owner Jephson Housing Association South and West, said: “It’s a terrible, traumatic thing to happen, and we’d like to offer all our sympathies.”