An approximately 130-year-old building suffered water damage, but no one was injured following a Tuesday night fire on South Franklin Street, according to firefighters.

Capital City Fire/Rescue responded to a water-flow alarm at about 10 p.m. in the 300 block of South Franklin Street, according to a CCFR social media post. Upon arrival, responders encountered smoke on the third floor of the building. A sprinkler system had been activated and occupants were evacuated, according to CCFR. Occupants reported hearing popping sounds, which led them to the fire, calling 911 and evacuating.

The amount of damage caused by the fire is undetermined, but an investigation identified a cause, according to CCFR.

It was determined a wood screw penetrating wiring on the third floor exterior deck made contact with copper wiring, which caused electrical resistance and enough heat to cause the wood to catch fire, according to CCFR. The fire was contained to inside the wall and ceiling spaces of the business.

When the fire traveled to the ceiling, near the point of ignition, a sprinkler head was activated and put out most of the fire, according to CCFR. Firefighters were then able to extinguish the remaining flames using little water.

• Contact reporter Jonson Kuhn at jonson.kuhn@juneauempire.com.