A female resident was hospitalized with smoke inhalation during the three-alarm blaze, which was called in around 4:15 a.m. and sent flames shooting up through the walls, severely damaging the Walnut Street home, Deputy Fire Chief Tom Loreto said.
Surrounding homes were evacuated as a precaution.
Mahwah firefighters were assisted by their colleagues from Ramsey, Wyckoff, Midland Park and Ho-Ho-Kus, among others. They had the blaze doused by 6 a.m. before hitting hot spots.
The Bergen County Sheriff's Bureau of Criminal Identification collected evidence so that county prosecutor's detectives could determine the cause and origin, authorities said.
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