An electrical substation at a manufacturing firm in Cleckheaton caught fire last night (Monday).
Fire crews from Cleckheaton and Odsal were called to Flexitallic, off Hunsworth Lane, at around 11.50pm.
A West Yorkshire Fire and Rescue spokesman said the fire began in an electrical substation on the side of the building.
Because the building was heavily smoke logged, it took 15 minutes for firefighters to locate the fire using thermal imaging cameras.
They then had to break into the substation and four breathing apparatus wearers brought the fire under control with dry powder extinguishers.
The spokesman added the fire caused damage to the electricity supply, but not to the building itself.
Northern Powergrid were called and crews used positive pressure ventilation fans and natural ventilation to clear the building of smoke.