CALUMET CITY, Ill. — Firefighters in Calumet City are battling a three-alarm fire at a multi-story apartment building. 

Per Chief Glenn Bachert, the blaze broke out around 7 p.m. in the 200 block of Park Ave. Emergency crews encountered fire on the second floor of the 312-unit apartment complex, radiating up the seventh floor and through the roof.

As a result of the blaze, multiple agencies were called to the scene to assist.

The fire remains active in the attic of the apartment building, Bachert added.

Three people, including one firefighter, were taken to a nearby hospital with minor injuries.

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First responders worked to evacuate the building.

The cause of the blaze is unknown. A fire investigation is ongoing.