BRIDGEPORT — Firefighters suspect arson may be the cause of an early Thursday blaze that damaged a former Remington Arms plant off Barnum Avenue.

As flames poured from what remained of the vacant building's roof, smoke wafted across the city's East Side, enveloping Bridgeport Hospital.

Officials at the scene were concerned about chemicals, asbestos and other materials left inside the aging industrial structure, closed over 15 years ago. The property is owned by developer Sal DiNardo, fire officials said.

Provisional Assistant Fire Chief Dominick Carfi said no one was injured in the blaze, which began at about 6:55 a.m.

Firefighters quickly brought the fire under control, despite being hampered by the unsafe condition of the building, Jersey barriers that blocked access and a chain-link gate that had to be cut to gain access, he said.

Carfi said homeless people were apparently living in the building, and are suspected of causing the fire. The blaze remains under investigation, he said.

"This could have been far worse," Carfi said. Flames could have leapt across the street to other sections of the abandoned factory, possibly igniting the entire block, he said.

Carfi said Metro-North Railroad was notified about the fire because its commuter trains run behind the building. But rail service was not disrupted.

The hulking complex is composed of three connected rectangular buildings. The fire apparently erupted in the middle section, firefighters said.

Carfi said firefighters were unable to access much of the interior because the structure's floors are no longer safe. He said the fire was primarily attacked from the exterior.

Firefighters climbed long ladders to spray water through already broken windows, and at one point used an unmanned ladder to hose down a upper section of the complex.

A city crane was brought in to remove a Jersey barrier from an entrance. On the other side of the complex, firefighters had to cut away a large chain-link gate so trucks could enter the property.

Carfi said fire equipment from across the city was initially dispatched to the scene. He said Fairfield sent two fire companies to cover the city's downtown fire headquarters. Normally, he said, one Fairfield company would be sufficient.

But the city recently closed Engine Co. 5 to help close a deficit in the Fire Department budget, and that meant extra Fairfield firefighters were needed to provide adequate coverage, he said.

Bill Cummings, who covers regional issues, can be reached at 330-6230.