Fire engulfed a disused factory in Grey Street, Darley, last Thursday night.
Bacchus Marsh CFA’s Lieutenant Tony Prouse said they arrived to find the old brick factory well alight as flames consumed the facade and internal wooden beams.
Holes were cut into the sides of the building to allow crews to gain access.
The cause of the fire is being investigated.
Information to Crime Stoppers 1800333000 or crimestoppers.com.au.