Firefighters are continuing to battle a stubborn fire at a commercial building in Mississauga this morning.

The fire broke out at a building on Wharton Way shortly before 2:30 a.m. and when crews arrived on scene, the structure was fully engulfed in flames.

Peel Regional Police were also called in to assist.

Reports from the scene indicate that the owner of the building, Maxxit‎ Systems, manufactures custom store fixtures and does architectural interior work for major North American retailers. Ten other tenants also reportedly lease office space in the building.

Employees were not working in the building when the fire started and no injuries were reported.

"We have a lot of projects on the go at the moment, a lot scheduled for the New Year. It was a very busy time and it is a very sad thing to see," Myles Davis, a project manager at Maxxit Systems, told CP24 at the scene.

"It couldn’t have happened at a worse time."

He added that the company is a family-run business that started about eight years ago.

"They have been growing in size leaps and bounds over the past eight years," Davis said.

"This is a huge blow."

Wharton Way north of Dundas Street will be closed as firefighters attempt to extinguish the blaze.

Mississauga Transit buses have been brought in to shelter employees as they arrive for work.

Platoon Chief Gord Smith told CP24 at around 9 a.m. that crews were still in "defensive mode."

"This building has collapsed down. We are in the midst of getting heavy equipment here so we can start to pull some of the rubble off the top so we can get down to the scene of the fire," he added.

The cause of the fire is not yet known and the Office of the Fire Marshal has been called in to investigate.