An inquiry is under way after a fire swept through part of the JCB factory in Staffordshire.
More than 80 firefighters battled for several hours to control the flames which started in a production building, in Station Road, Rocester.
A large cloud of smoke spread across the area and staff were led from the single storey building.
Ambulance teams treated people at the scene but no one was seriously injured.
The fire started shortly after 0800 BST on Friday and spread to a roof space.
Chief Fire Inspector Graham Moltby says the fire was made worse because of oil in equipment being stored in the building.
JCB's director of security David Bufton praised the fire service for their quick response.