A MYSTERY fire has wrecked a two-storey office on a demolition site.
At its height the blaze, on the former Hollidays Dyes and Chemicals plant on Leeds Road, was tackled by more than 80 firefighters from all over Yorkshire.
Fire investigators are now examining the cause of the blaze.
The building was part of the old site, but was used by the demolition company for offices and a canteen.
It was constructed of brick, wood and felt.
The site is currently being demolished and redeveloped.
Firefighters were called out at about 7.30pm on Saturday.
They kept returning to the scene overnight and on Sunday to keep damping down the building.
Station Officer Alvin Crisp, of Huddersfield, said: "The structure of the building was too weak for firefighters to enter and enable us to reach the seat of the fire."
The premises are expected to be demolished.
The cause has not been established yet.
Twelve appliances were called to the fire, which engulfed a two-storey building measuring 75 by seven metres.
Six pumps were backed up by three special appliances and three support units.
Four water jets were used to tackle the blaze along with a ground monitor.
Old buildings used by the chemicals giant have gone and are being replaced by new units.
These include giant warehouses to form the headquarters of the Poundstretcher retail chain.