Nashua, NH – An 11-year-old girl helped save her family from carbon monoxide poisoning Tuesday night.

Fire officials said five people were treated for carbon monoxide poisoning, but it could have been worse if they hadn’t evacuated their Northwood Drive home.

Officials said family members began feeling sick after a faulty furnace allowed carbon monoxide to build up in the home.

“We are not sure what really happened,” resident Dalbrhhe Singh said. “There was carbon monoxide. That’s what the people said.”

Fire Assistant Superintendent Adam Pouliot said carbon monoxide levels were measured at 150 parts per million.

“One hundred fifty parts per million is quite high,” Pouliot said. “The body will start to feel effects at 35 parts per million, and 35 parts per million is our action level.”

Relatives said 11-year-old Nana Singh realized something was wrong when members of her family said they didn’t feel well, and she noticed an unusual odor. Nana called her father, who told her to get everyone out of the house and call 911.

All five people home at the time were taken to a hospital with symptoms of carbon monoxide poisoning.

“Some of the symptoms of carbon monoxide poisoning are dizziness, lightheadedness, short-term memory loss, nausea,” Pouliot said.

Dalbrhhe Singh said the family members are all fine.

“They are all good,” he said. “They’re at a family and friend’s house.”

Gil Rodrigue of Gil’s Appliance Repair said the furnace hadn’t been maintained. Although the furnace will have to be replaced, Rodrigue said the family is lucky that a carbon monoxide leak was the only problem.

“The gas valve on this unit has been charred, which means it’s been subjected to a flame, and if the top was melted off, gas would have just started flowing in,” he said.

Fire officials said everyone should have working carbon monoxide detectors in their homes. If a leak is suspected, get everyone out of the house and leave doors and windows closed. That will help fire officials trace the leak to its source.