The family of a 94-year-old Littleton woman who died from carbon monoxide poisoning has filed a wrongful death lawsuit against Irving Energy, the company that maintained and serviced her oil furnace.

Lawyers said firefighters found Catherine Braun at the bottom of stairs near her furnace on Jan. 30, 2016.

She was asphyxiated by carbon monoxide and other fumes that came from the furnace after it malfunctioned, said Daniel J. Corley, the Concord lawyer suing on behalf of her son, Gary Braun of Nashua.

“It is a tragedy that this active woman died as a result of the defendant’s failure to properly maintain the equipment. She had a loving family and was young for her age,” Corley said.

The lawsuit lists Highlands Fuel Delivery, which does business as Irving Energy, as the defendant. An email to the New Hampshire office was not immediately returned.

In a statement, Corley’s law firm cited a report by the Grafton County Attorney, which indicated that the vent pipe and other items were not properly attached according to industry standards; the pipes likely blew off and released poisonous gas into the home.

The statement does not specify who had worked on the furnace, but it said Irving was responsible for making sure the vent and flue pipes were properly secured.

According to the lawsuit, Grafton County officials had investigated but opted not to file criminal charges. Braun was a widow and had one son.

“We want to prevent other people from suffering similar deaths,” Gary Braun said in a statement.

The lawsuit was filed recently in Hillsborough County Superior Court-South.