A Blandford street was closed on Monday evening and a family evacuated from their home and left homeless when the cob wall at the side of their property collapsed into the yard next door.

Anita Roberts was in the shower when her son, George, 17, shouted that the wall had fallen, taking a bedroom cupboard on the first floor with it.

“I didn’t believe him at first,” said Anita, who went outside in her dressing gown and slippers to find the ground and first floor open to the elements and giant cracks in the wall above.

It wasn’t long before the second floor crashed to the ground, leaving only the chimney standing and exposing the internal gas fire flue up the side of the building and the rooms inside.

George, 17, who serves with the Royal Navy and was only at home because he had broken his wrist a few weeks earlier, said: “I heard the crash and went downstairs to find people knocking on the door telling me the wall had collapsed.

“I had been sitting only a few feet away in my room on the second floor.”

Husband Simon Roberts was at work at BOCM when he received a phone call from home giving him the news, and Dorset Fire and Rescue were alerted at 8.15pm. They dispatched a retained crew from Blandford to check that the building was relatively safe, and remained on the scene for nearly four hours and were joined by full-time staff.

A spokesman said: “The occupier had already contacted building control, and the fire service isolated the gas and electrics. A Red Cross Fire Support Vehicle attended to provide temporary accommodation for a couple of hours for residents who were unable to stay in the house, and occupants of two neighbouring buildings who were also evacuated until emergency accommodation could be found.”

The fire crew cordoned off the street outside, where neighbours, who only a few days earlier had gathered for their ‘Big Lunch’, gathered again to offer support, and later in the evening, Dorset Police attended to fully close the road.

Mrs Roberts, a mature student training to become a nurse who had been preparing for to sit an exam the following day, said: “It’s a lovely house – we’ve lived here for 17 years.”

She said the house, built in the late 19th century and one of a number of grade II listed buildings in the street, was rented, and that her landlord Paul Cracknell was devastated by what had happened.

Mr Cracknell, a carpenter and builder, gave the family temporary accommodation at his home in Milldown Road, and was back at the scene next day, where contractors Mark Farwell had been brought in to remove the rubble and clear the site.

“The next step will be to erect scaffolding to shore up the building, but I’ve no idea how long it will take to repair. We inherited the house through my wife’s family, and she was brought up there, but we didn’t realise the whole wall was cob because the rest of the house is brick.”

Mr Roberts, who had taken the week off work on compassionate leave to deal with the emergency, said the family were now staying with neighbours, but it was unlikely they would move back to the house when it was repaired. He has already visited local estate agents.

A number of the houses in the street have cob walls, and it is understood that one which stood next door to Mrs Roberts’ home collapsed some forty years ago, leaving a gap in the street. The natural building material made from sand, clay, water and straw is used in thousands of houses and buildings in the South West, some dating from the 14th century, but is susceptible to extreme wet weather.