Historic mansion Kelsale Hall in Suffolk was destroyed in a major fire
Flames tore through 19th century Kelsale Hall, near Saxmundham, Suffolk, and it collapsed from the inside.
A dozen fire crews tackled the blaze which broke out after 6pm on Wednesday but said it was too dangerous for crews to tackle from the inside.
Area commander Ian Bowell said: "It was totally unsafe to go in there. Unfortunately, that's quite a significant loss.
We haven't been able to save as much as we would like
Area commander Ian Bowell
"It's a sad loss and we haven't been able to save as much as we would like. But given the circumstances, we've done our best."
The mansion, which was privately owned, stood in a 3,500-acre country estate.
Several people were reported to be inside the property at the time the fire was reported but no-one was injured.
However, Mr Bowell said no one was injured and the worst consequence was the loss of the historic building itself.
The Grade II listed mansion collapsed from the inside
It is set several hundred metres back from the A12, and firecrews had to join together nearly a kilometre of hose pipe to reach the building.
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Kelsale Hall is known for its well-established game bird shoot, which has been running for more than 30 years.
The farmland was put up for sale in 2011 when it was valued at more than £19million.