PORT OF CATOOSA - A building at the Port of Catoosa is heavily damaged after a fire burned for hours.

Firefighters said they weren’t able to start putting out the fire right away because nearby chemicals raised some concerns.

Around 2:15 Saturday morning, sparks flew at the Port of Catoosa.

Three employees escaped the burning building, but the threat of dangerous chemicals kept firefighters from putting out the flames.

Tulsa Fire Captain Jim Moseby said, "It's very nerve-racking when you do approach a building with a lot of chemicals in it. Any firefighter is gonna be very leery of that."

Moseby said anytime firefighters go to the Port of Catoosa they look for placards on buildings before they start using water.

"It's a W with a slash through it at the bottom. It's gonna tell us right away that this building is not gonna allow us to put water on it," he said.

The captain said the chemicals inside could have a bad reaction with water, intensifying the fire and becoming more risky for firefighters.

Moseby said, "Iodine tetrafluoride, I believe, was the chemical used at this particular facility. It was in a building adjacent to the fire area."

Hazmat crews monitored the air for several hours, making sure it was safe for firefighters to put water on the flames.

After about four hours of testing the air, firefighters could get to work.

"It's kinda hard to watch a building burn from a distance because our nature is to put the fire out," Moseby said.

The fire destroyed several offices at Advanced Research Chemicals.

Tulsa Port of Catoosa Manager of Operations Brad Banks said the company has been there for about 30 years.

"They're a pretty resilient company, and they're a pretty successful company, and I hope that they do decide to rebuild," Banks said.

No injuries were reported.

The State Fire Marshal's Office said the Port of Catoosa fire "is believed to have originated in the chemical ventilation system, possibly caused by chemical reaction."