Devon and Somerset firefighters were called to a fire at a derelict building on the A30 Sherborne Road Westbound at 2.20am this morning.
By 5am, seven fire engines along with two aerial ladder platforms, a water carrier, an incident command unit and a welfare appliance were used at the scene by several fire officers.
The main workshop space in the building was well alight. Part of the building also collapsed.
The road remains partially blocked and there is now heavy traffic between Southville and Wyndham Street.
The incident is still ongoing.