A fire swept through a group of factories in Melbourne's west overnight, destroying a jumping castle hire company and causing damage to at least two other businesses.
It took 50 firefighters and 16 appliances to battle the blaze, which damaged a complex of factories in Hoppers Crossing.
Speaking to Fairfax Media early on Thursday morning, Michael Andrew, the owner of A&A Jumping Castles, said he had not yet been made aware of the extent of the damage to his business.
"I may have just lost my livelihood," he said.
The Melbourne Fire Brigade was alerted to the fire shortly after midnight.
An hour and 40 minutes later, it had the fire under control, but at 7am there was still smoke and heat emerging from the premises.
Four trucks remained on site to monitor the situation.
"When we got there the fire was well evolved," said Western District Commander Marcus Baker.
"One factory was completely destroyed."
Initially, firefighters targeted the blaze both internally and externally, but when cracks in the concrete slab walls were discovered, the MFB withdrew its crew from within, fearing the walls might collapse.
Fighting the fire solely from the outside complicated matters, prolonging efforts to extinguish the blaze.
Police attended the site on Thursday morning to investigate the cause of the fire. They are treating the incident as suspicious.
Building surveyors were also on sight, inspecting the walls to understand whether the cracks were only on the surface or whether they represented deeper, structural damage.
If they find the walls are no longer structurally safe, the walls may need to be knocked down.
The MFB said its investigators would be attending the site later in the morning to conduct their own investigation into the cause of the fire.
The website of A&A Jumping Castles was hacked.
No one was injured in the fire, police said.