Norwich ― A fire early Tuesday in an apartment at the Lofts at Ponemah Mill apartment complex temporarily displaced 23 people from 14 units.

Firefighters responded to the 300-unit complex at 607 Norwich Ave. at about 3 a.m. for a report of a fire alarm, Taftville Fire Chief Timothy Jencks said.

The building was already partially evacuated and Jencks said there initially were no obvious signs of smoke or fire but evidence the sprinkler system had activated. Firefighters forced their way into a fourth-floor apartment to find smoky conditions and a man who was unable to get out without help from firefighters, Jencks said. The man was taken by ambulance to Backus Hospital for treatment of possible smoke inhalation.

A living room chair that had been on fire in the man’s apartment had been extinguished by the unit’s sprinkler system. Jencks said the sprinkler system worked as designed and stopped the spread of the fire but also led to water damage in the apartments below.

The Norwich Fire Marshal’s Office is investigating the cause of the fire.

The city’s building department is working with the property manager to determine the extent of the water damage. Jencks said the city’s social services department also was on scene with Red Cross representatives to help relocate residents. The Red Cross, in a statement, said it is aiding 14 families - 19 adults and four children.

Also responding to Tuesday’s fire was American Ambulance, Occum and City of Norwich fire departments.