ROTTERDAM — Investigators are still trying to determine the cause of a fire that consumed a 22,000-square-foot section of Building 6 at the Rotterdam Corporate Park, but officials do not believe it is suspicious.

More than 100 firefighters from eight companies around Schenectady County battled the blaze, which broke out in a section of the Distribution Unlimited warehouse shortly before 5 a.m. County Fire Coordinator John Nuzback said there is no official cause for the fire, which was contained from spreading to other areas of the sprawling complex by the structure's safety features.

"We don't believe it's suspicious," he said late Wednesday afternoon.

Nuzback said the fire was first reported after the building's sprinkler system triggered an automatic alarm. Flames spread quickly through the paper products stored in the warehouse. He said the building's fire doors and fire walls — features that were built into the structure when it was an Army depot — likely prevented the fire from spreading during the initial attack by firefighters.

"The fire walls and fire doors are what contained the fire to that section," he said.

Nuzback said two workers were evacuated from the burning warehouse, along with roughly 40 employees from other areas of the building. Firefighters were also forced from the warehouse when a large section of the roof collapsed.

There were no injuries reported. State and county fire investigators were sifting through the warehouse wreckage during the afternoon, but still hadn't pinpointed the cause.

The Galesi Group owns both Distribution Unlimited and the sprawling complex off Duanesburg Road. David Buicko, Galesi's chief operating officer, praised the efforts of firefighters to extinguish the blaze.

"They did a great job," he said. "The collaborative effort from the various departments that came was terrific."

Buicko was unsure how much damage was done to Building 6 or the amount of product his company lost. He said the amount of damage to the overall park wasn't extensive, considering the 260,000 square feet contained in Building 6 alone.

"I can't even smell any smoke [in my office]," he said.