But much of the collection which includes paintings, furntiure and an extensive array of ceramics, were damaged or destroyed.
A fire damaged bust at Clandon Park (Rex Features)
It is thought that the nearby infant school was being used to store some of the artefacts that were pulled from the burning mansion. The school posted on its website saying it was closed for the day because of the fire.
It is not yet clear whether the collection of a military museum in a cellar area, which includes one of the footballs kicked across no-man’s land on the first day of the Battle of the Somme in 1916 was also lost.
But Dame Helen Ghosh disclosed that the interior of the Grade-I listed property had been left almost entitely affected by fire and smoke damaged.
Only one room is believed to have been left relatively untouched, she said.
Pictures taken on Thursday morning show that the extent of the devastation, with daylight visible through upper windows where the roof was destroyed.
— NT Press Office (@NTPressOffice)
April 30, 2015
“The house is essentially a shell, with most of the roof, lintel and the ceiling and floors fallen into the bottom of the building,” said Dame Helen.
“It’s a very upsetting sight to anyone who loved this wonderful and historic building.”
She added: “We have a very well-rehearsed plan to get key items out of houses.
“We have saved a certain amount of the contents but until we have got a chance to assess we can’t really say how much.”
Staff and volunteers were safely evacuated when the blaze broke and some historic artefacts were salvaged as the blaze took hold (INS)
She added that it was too early to say what the future holds for the property, which was used in the 2008 drama The Duchess starring Keira Knightley.
But she said the experience of National Trust team members who helped in the aftermath of a fire at one of its properties in Suffolk in the 1990s would be used.
“There is perhaps one room that is relatively untouched but, other than that, the interior is extensively damaged,” she explained.
“The external walls are still standing.”
One of the footballs kicked across no-man’s land on the first day of the Battle of the Somme in 1916 was lost
She added: “The most important thing for me is that no one has been hurt in this awful fire and that everyone is safe.
“But it has been heart-breaking to witness the terrible damage to this wonderful mansion, which means so much, to so many people.
“This will come as a terrible shock and a devastating personal blow to all our devoted staff and volunteers.”
Thick black smoke could be seen pouring from the building and nearby resident Phoebe Grant said flames were “shooting out of the building”.
Others reportedly heard loud bangs coming from inside.
Clandon Park was built in the 1720s and contains a large collection of 18th century furniture, porcelain and textiles. It has been managed by the National Trust since 1856 and is a popular venue for weddings.
A member of The National Trust team with so of the rescued items from the fire (North Downs Picture Agency)
Some 16 crews were deployed to the scene along with three aerial ladders and three water carriers.
One of those affected by the fire is IT consultant Peter Page, who is due to get married there next month.
So sad about Clandon Park. Due to get married here on 30th May. Can any wedding venues in Surrey let me know if they have any availability?
— Peter Page (@PagePeter1)
April 29, 2015
Another person affected, Mark Nickols, posted: “My brother was supposed to be getting married at Clandon House on Friday. We now have 24 hours to plan a wedding.”
Fire damaged timbers in the Marble Hall are seen through a broken window at Clandon Park (Getty Images)
Dame Helen said one wedding was due to be held on Friday, and a team was contacting the bride, neighbouring properties and the registrar about alternative arrangements.
“From now it will be a slow process of an investigation by the fire service and then by our own specialists, and taking time about the future,” she added.
Roger Childs, of Surrey Fire and Rescue Service, said a “significant amount” of highly valuable items were able to be retrieved from the blazing Grade-I listed property.
The intensity of the flames burnt away floorboards and ceilings, but Mr Childs refused to speculate on whether an electrical fault caused the fire.
He told BBC Radio Surrey: “The fire originally started, we believe, in the basement, and because it’s Grade-I listed, the fire spread through these uncontained voids and it quickly spread through to the roof.
“The original crews on the scene had to deal with a developed fire as soon as they got to the scene. It’s significantly damaged across the whole of the building.”
Structural engineers from the local authority were due to assess the outer walls of the stately property to determine whether they are safe, Mr Childs said.