(Reuters) - The search for three firefighters feared dead in a huge warehouse blaze could take days because the building is so dangerous, fire chiefs said on Sunday.
More than 100 rescue officers will conduct an "inch by inch" search of the gutted warehouse in Warwickshire.
One firefighter has already been confirmed dead after the roof collapsed as he tackled the massive fire on Friday. Three colleagues are still missing.
Warwickshire's assistant county fire officer Jon Hall said they had a 36-hour plan to search the structure.
"It may take us longer," he told a news conference. "We are trying to get into an extremely dangerous structure and search for whatever is in there."
There is no evidence to support reports that there may have been workers inside the vegetable packing warehouse, he added.
The names of the dead firefighter and those missing have not been released. Police and fire service liaison officers are supporting their families.
More than 80 firefighters from Warwickshire, Herefordshire, Worcestershire and the West Midlands worked through the night to bring the fire under control.
The cause of the blaze in Atherstone-on-Stour is not yet known. Police say it may have been started deliberately. A police cordon is in place.