A fire that broke out at a Derby car park on Friday is thought to have been caused by overheated machinery.
Firefighters investigating the incident believe it began in an air conditioning unit in the car park on top of the city’s Assembly Rooms venue.
The blaze broke out at around 5.20pm on Friday and was brought under control by 7.30pm.
Around 75 firefighters and 16 fire engines were called to the scene as the inferno produced 40ft high flames above the city’s streets.
The Assembly Rooms are expected to be out of action for at least eight weeks while repairs are made to the building.
“There is currently a joint investigation taking place but we are confident it could be over-heated machinery of a motor in the room,” Kam Basi, assistant chief fire officer for Derbyshire Fire and Rescue, said.
“The thick black smoke was caused by the materials that had burnt in the room and that is why the smoke was so thick and dark.
“The room has been severely damaged and there has also been minor damage to the Assembly Rooms.”
Investigators returned to the scene over the weekend in an attempt to uncover what the fire started, with sources citing the air conditioning unit as the root of the blaze.
On Saturday afternoon the car park was cordoned off “for safety reasons” amid fears that debris from the roof of the building may be blown down due to high winds.
Crowds gathered outside the 100ft structure on Saturday to take photographs and see the damaged building themselves.
All performances scheduled for the Assembly Rooms Great Hall and Darwin Suite have been cancelled for at least a week, until another venue can be found.
Copyright Press Association 2014