The two-alarm, 6:30 p.m. Sunday blaze on Old Farms Road posed an "additional hazard of ammunition exploding due to the heat of the flames," according to Waldwick firefighters, who were among the mutual aid responders.
An initial report of surrounding homes being evacuated couldn't be confirmed.
Valley Hospital BLS treated the firefighters at the scene.
No other injuries were reported.
Among the other mutual aid responders, at the scene or in coverage, were firefighters from Allendale, Hillsdale, Ho-Ho-Kus, Park Ridge, Ramsey, Woodcliff Lake and Wyckoff.
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