Members of the West Amwell Fire Company responded to the blaze on Rocktown Lambertville Road just before 4:45 p.m., the department said in a Facebook post.
Fire crews stretched 200 feet of fire hose to help douse the blaze, which was placed under control within 20 minutes, authorities said.
Additional crew members arrived at the scene to assist with overhaul, and all units were cleared by around 5:40 p.m., authorities said.
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