Firefighters in Portsmouth, NH put out a small fire at the old Joe's New York Pizza on Congress Street on Thursday night.

Fire Chief Todd Germain said on Friday that emergency rescue crews were called to the unoccupied space at 8:50 p.m. It was still early enough that there were people around in downtown Portsmouth to report it.

Courtesy Photo

The fire was caused by the improper storage of oil-soaked, wood finish stain rags, leading to a spontaneous combustion of the materials.

Spontaneous combustion is a phenomenon in which a chemical substance unexpectedly bursts into flames without an apparent cause.

Courtesy Photo

Firefighters forced their way through the front door of the restaurant, which is currently under renovation, and quickly extinguished the fire with a hand-line from Engine 1.

Nobody was injured in the incident and crews returned to service at 10:01 p.m., Germain said.

Contact Managing News Editor Kimberley Haas at Kimberley.Haas@townsquaremedia.com.

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