Firefighters who responded within three minutes were met by flames on the first floor of the 2½-story Lunn Avenue home shortly after 1 p.m., Bergenfield Fire Chief Edward J Kneisler III said.
"Because the fire was extending to the upper floors, a second alarm was requested," the chief said.
Kneisler declared the fire under control in about 45 minutes.
A firefighter was treated at a local hospital for a minor arm injury, the chief said, adding that the residents checked out OK when evaluated by the Bergenfield Volunteer Ambulance Corps. The American Red Cross was assisting them with temporary shelter, he said.
Kneisler thanked the ambulance corps, borough police and its dispatchers as well as the mutual aid responders.
Those companies at the scene included Tenafly, Dumont, New Milford and Englewood, he said.
"Units from Dumont, Oradell, Teaneck, and Cresskill covered Bergenfield for additional emergency calls," the chief said.
The cause remained under investigation, Kneisler said.
PHOTO GALLERY: BT FIRE PHOTOS
Click here to follow Daily Voice Bergenfield and receive free news updates.