Fire investigators were in Newcastle on Wednesday morning to begin their inquiries into a blaze that ripped through a workshop in the Lovells Springs complex at Carrington on Tuesday.
Fire and Rescue NSW said on Wednesday the cause of the fire was yet to be determined, but it was not believed to have a suspicious origin.
The fire broke out in a room used for powder coating at about 5.20pm.
Firefighters from the Newcastle station called for back-up as they were travelling to the scene, after seeing the amount of smoke on approach - with a dozen crews ultimately working to put out the Parker Street blaze.
The Newcastle Herald understands that the fire was contained to one part of the building, with serious damage kept to about 20 per cent of the facility.
Seventeen workers were evacuated - one was taken to hospital for treatment for smoke inhalation.
Police said the damage bill was estimated to be about $1 million.
