Bergenfield, NJ – Four residents are “so, so lucky” that they called 911 when they smelled gas in their Terrace Street home Wednesday morning, the fire chief said.

Firefighters discovered the problem wasn’t gas; it was a lethal dose of carbon monoxide and the home’s carbon monoxide detectors weren’t working, Chief Jerry Naylis said. Readings showed the gas’ levels at more than 300 parts per million when a normal reading is between 5 and 6 parts per million, Naylis said.

“Another hour and four people would have been fatalities,” he said.

Carbon monoxide is odorless but the home’s boiler wasn’t working properly and that’s why there was the smell of gas, Naylis said. Between the malfunctioning boiler and a disconnected flue pipe, it was a “very, very dangerous situation,” he said.

“Next month when they celebrate Thanksgiving, they’ll have a lot to be thankful for,” he said.

One of the residents was taken to be evaluated at the hospital by the Bergenfield Volunteer Ambulance Corps, Naylis said. The fire chief urged residents to check their boilers, furnaces and carbon monoxide detectors as winter approaches.

Nearly a year ago, two Clifton residents were killed and 12 others were sickened at a Passaic recording studio after a gas leak. Authorities measured the carbon monoxide levels then at more than 1,000 parts per million.