By Bianca Buono

bbuono@abc6.com

By Bianca Buono

@BBuonoABC6

The view of downtown Providence was obstructed by black smoke pouring from the roof of the Textron building around 10:30 Sunday morning.

"You could see flames. And you could see the flames turn to dark smoke and the dark smoke turn into lighter smoke,” said Providence Mayor Jorge Elorza.

Some bystanders watching smoke pour from one of the tallest buildings in the city couldn’t help but think the worst.

"I didn't know if perhaps it was like a small plane that maybe clipped the building or something,” said Gilbert Lourenco who witnessed the aftermath of the fire.

Thankfully that wasn't the case. Fire officials linked the cause to a large heating and cooling system on the roof. But tackling the 25-story building was no easy job.

"You've gotta bring a lot of equipment up to that roof top. So we used an elevator but there's a lot of equipment and then the last two floors you have to climb up to the roof top,” said Public Safety Commissioner Steven Pare.

Nearly sixty firefighters were on the scene and more than a dozen trucks lined the streets below. They somehow limited the damage to a single HVAC unit on the roof and extinguished the fire after about an hour.

"Luckily we didn't have it penetrate into the building. I mean you have that, especially up on the top floors, it causes a lot of damage to those floors underneath so luckily we were able to knock it down and save the building and confine it to the roof top,” Pare said.

At the start of the fire, the building was empty with the exception of security personnel who are all uninjured and accounted for.

"We're very fortunate it happened on a weekend and on a Sunday when there's very few if any people in the building,” said Textron Communications Director David Sylvestre.

Fire officials are investigating what specifically went wrong with the HVAC unit.

"We have a maintenance staff that works full time at Textron and they're always checking these mechanical systems,” Sylvestre said.

One firefighter was hurt but officials say her injuries are minor and she's being treated in the hospital.

A Textron rep tells ABC6 that there is no water damage in the building and they expect business to operate as usual on Monday.

© WLNE-TV 2015