SUN PRAIRIE, Wis. -

One resident was displaced after a fire at an apartment building in Sun Prairie Tuesday afternoon, officials said.

The Sun Prairie Fire Department responded to a report of a structure fire at 3:59 p.m. on South Bird Street.

Crews reported seeing smoke from a first-floor apartment, according to the report. An off-duty Sun Prairie firefighter entered the apartment to assist an occupant who had mobility issues out of the building.

Firefighters found heavy smoke and fire in the kitchen area, fire officials said. Crews deployed hose lines and knocked down the fire, stopping the fire from spreading to any other units. Smoke alarms were sounding, which also activated the alarm system in the building. The alarms alerted residents to evacuate. There is no sprinkler system in the building. After the building was ventilated, the residents were allowed back into their apartments.

No injuries were reported and the American Red Cross was contacted to provide assistance to the resident who was displaced.

Fire officials reported fire damage was contained to the kitchen with smoke damage throughout the unit. There was not an estimate on the cost of damage Tuesday night, according to a news release.

The cause of the fire is still under investigation.