CHICAGO (CBS) — Firefighters are working to extinguish flames at an apartment complex in Prospect Heights.

Firefighters report heavy fire coming from a large, three-story apartment complex. According to the Prospect Police Department it is a five-alarm fire.

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Fire officials were called to the 800 block of Macintosh Court around 1:30 p.m. Wednesday.

Nine different fire departments are on the scene helping to fight the flames.

Three residents and a firefighter have been treated for smoke inhalation. They were taken to a local hospital, but have been released.

A number of residents have been displaced. The exact number is unknown at this time.

The Prospect Heights Mayor says four buildings are uninhabitable. He says each building has 24 units, each housing anywhere from one to four people.

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More than 100 people have been displaced.

Officials are warning to stay away from the area of Apple Drive and Plaza Drive in order to allow emergency response agencies to extinguish the apartment building fire.

The American Red Cross of Chicago & Northern Illinois tweeted they have 10 volunteers responding to the fire to provide assistance, food, and water to the people affected.

The Prospect Heights Fire Chief says fire officials will be on the scene for several more hours, possibly throughout the night, to extinguish the fire.

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This is a developing story.