BOSTON -- A fire destroyed a row of small businesses in Boston's Fenway neighborhood early Tuesday morning.

Video | Fire Images

NewsCenter 5's Gail Huff reported that the fire broke out at about 2 a.m. at Thorntons Fenway Grill at the corner of Peterborough and Kilmarnockabout.

Firefighters had to run through an apartment building to make sure that the residents got out of the building.

"He was saying, 'Get out. Get out. There is fire,'" resident Lilla Anderson said. "I looked out and there was a big blaze. It was going, and it just spread -- just like that, like it had gas in it."

The flames destroyed six restaurants and a dry cleaner.

"It was a good four or five hours that the fire was out of control," Boston Fire Department Deputy Chief Robert Dunderdale said. "In the colder weather, it was very slippery. It was tough getting in position and getting lines in position."

Two firefighters who slipped on the ice were injured, and 23 elderly residents who lived in an adjoining complex were evacuated.

"The smoke was pouring in. The alarms were going off," one resident said.

Smoke from the fire billowed down the street, forcing the evacuation of another 100 people.

"The smoke permeated the building, causing elevated carbon monoxide levels, so they evacuated it due to the health concerns with the carbon monoxide," Boston Emergency Management Director John Hardiman said.

An emergency shelter was set up at a school across the street. Residents watched as nearly 100 firefighters battled to keep the flames from spreading down the block.

"We have no idea how the fire started. We've had some people on the scene. We are conducting some interviews," Dunderdale said.

Mayor Thomas Menino said city officials are working closely with the businesses ravaged by the fire.

"It is a terrible tragedy to lose these popular businesses in the Fenway. It's a huge loss for the community, and it means people are now out of their jobs, "Menino said. "At the city level, we're working collaboratively to do everything we can for those involved. The most important thing we can do right now is to help these folks get back on their feet and reopen their businesses."

The fire is estimated to have caused about $5 million in damages to the businesses. Officials said that engineers were truing to assess the structural integrity of the building to determine whether it could be rebuilt or if it would need to come down.

Menino said a team of staff would work closely with the building's business owners in the coming days and weeks to offer guidance and assess the exact needs of each business in an effort to expedite the process of reopening.