Fire has gutted a Grade II listed mansion used as a campus by the agricultural college at Moreton Morrell.
Firefighters, with 15 engines and five hydraulic platforms, are this morning continuing to tackle the blaze at Moreton Hall, which broke out at about 3.45pm yesterday (Thursday).
Some 80 officers were involved in the operation overnight and, such is its intensity, the fire is not expected to be extinguised until sometime tomorrow (Saturday).
See a video of the incident here.
Staff were evacuated and the area cordoned off as crews from Oxfordshire, Hereford, Worcestershire and the West Midlands rushed to the scene.
It is believed the majority of students were away for their Easter holidays.
This morning the damage to the Georgian-style mansion, built in the early 1900s, was described as "around 60 per cent". Another fire service spokesman said: "the building is completely gutted. It's gone."
Deputy county fire officer Glen Ranger said: "This is a large incident which has required us to deploy resources and specialist equipment from across Warwickshire and neighbouring services.
"We are still in defensive mode tackling the blaze and expect to be in attendance for another day or so.
"The cause of the fire is as yet unknown, but will be investigated once the operational side of the incident is complete."
Ambulance crews are on site ready to offer medical support to firemen.
Speaking from the scene late on Thursday night, ambulance officer Nigel Wells said:
"At this stage it is not thought there is anyone in the building and no-one has been injured. The site was a beautiful manor house, used as part of Warwickshire College. It was also used as a conference centre and for weddings and was a historical landmark.
"It is a real shame and very sad to see it all go up in flames."