MANCHESTER - Fire officials are investigating the possibility that a fire that displaced three families from a triple-decker Tuesday was caused by heaters being used to rid the structure of bedbugs.

There were 14 people, including five children, living in three units at 45 Schuyler St. on the city's West Side. Firefighters were able to extinguish the fire before it consumed the structure, but the building was left uninhabitable. Five ladder trucks responded at 2:50 p.m., and flames were doused by 3 p.m.

None of the tenants were in the building when the fire broke out, because exterminators were treating the structure for bedbugs.

District Fire Chief Jim Michael said the treatment involved using heaters to raise the temperature in the building to a point that kills the bugs.

"They heat the house up to 135 degrees," Michael said at the scene of the fire.

Michael added that the cause of the fire remains under investigation, but he said the use of the heaters is "something we're looking at."

The former residents of the building's second-floor unit were more certain - and angry - about the cause of the fire.

"From the information I got, they put in too many heaters and they weren't paying attention enough. They didn't realize what was going on," said Roger Richard, part of an eight-member extended family.

The fire started in the family's apartment, and it was the only unit that had the heaters in it, according to Richard.

Members of the family were gathered at the building Tuesday evening, where a Red Cross truck was parked to provide assistance. The organization is helping Richard and his family stay at a local hotel.

Richard and other members of his family said when they came by the building earlier in the day, the exterminators were sitting in a truck smoking cigarettes and looking at their smart phones.

The family was able to rescue their two cats, which were on the deck while the building was being treated.

Tiffany Hargreaves, another member of the household, said she was visiting a friend in the hospital when she got the call about the fire. "I burst into tears," she said.

She said the family was "devastated and angry."

Members of the family said they have a "good landlord," and that he was responsive to problems, including the bedbugs, which had only recently appeared.

The landlord, Christian Monfet, was also at the scene Tuesday evening.

"I just want to make sure the tenants are safe. That's my priority," he said. "We're going to get the building secured tonight."

Monfet added, "I just put on a new roof. It seems like every step forward, we have to take a step back."

As for the possibility that the exterminators were to blame for the fire, Monfet said he would wait for the investigation to be completed. He declined to identify the extermination company.

He said the building was insured and he hoped to have it rebuilt as soon as possible.

"I have great tenants," he said. "We're going to get through this, and the building will be even better than before."