Fire Capt. Robert Newton said the building located at 314 Main St. was an old paint storage shed and part of the old GEM Industrial Complex and has been empty for a number of years.
"It's still under investigation by our fire service investigators," said Newton.
"There's no power to the building and no heat to the building," he added.
The building was mostly corrugated sheet metal with wood support beams and a wood roof, so the age of the materials helped the fire spread, said Newton. The building was probably built in the 1920s or 1930s, he said.
The building was about 40 feet long and 20 feet wide and ranged between one and 1 1/2 stories tall, said Newton.
No other buildings were damaged by the fire which Gardner firefighters extinguished in just over two hours Wednesday morning, said Newton. The Fire Department received the call just after 5:30 a.m.
The main building for the GEM Industrial's was destroyed by a fire in the 1990s, said Newton.
Hubbardston Fire Department sent an engine to cover the Gardner station.
