Fifteen fire engines have been tackling a major blaze at the old Walkley Clogs building in Mytholmroyd this evening.
Firefighters from around West Yorkshire were called to the scene, on Burnley Road, at around 5.45pm.
At its height, 15 engines were at the scene but West Yorkshire Fire and Rescue Service said their presence is being scaled back.
The A646 Burnley Road remains closed and diversions are in place. Motorists are being advised to avoid the area.
Rowanna Ewings described seeing the smoke from her farm in Mytholmroyd. She said: "I was really shocked to see the black billowing smoke down in the valley of what I now know is Walkley Mill.
"Because we are up on the hillside we have a good view of things happening and the mill is directly below us.
"I think its really sad that this has happened to such a historic local landmark building.
"I have so many memories of it as I’m sure many people of Mytholmroyd and Hebden Bridge do too, I had my first job there as a teenager."
Fellow eyewitness Jade Kilbride said the building looks like it is beginning to collapse.