It’s believed a portakabin blaze in Cleckheaton last night was started deliberately.
Fire crews from Cleckheaton were called to Foundry Terrace at around 10.40pm.
When they arrived they found a wooden portakabin, which is currently being used an office, ablaze.
A West Yorkshire Fire and Rescue spokesman said firefighters got there just in time, as the fire was beginning to quickly spread.
He added that it looked as though someone had lit some paper to get the fire going.
Crews attacked the fire from both sides of the building using hose reels. Police are investigating.