Officers responded around 11 a.m. to the 3300 block of West Marquette Road near Marquette Park and Chicago Lawn, CPD said.
Three victims, two males and a female whose exact ages were not yet known, were found inside of an apartment. They were pronounced dead at the scene.
The victims' names have not been released.
It is a three-story apartment building, and ABC7 was told told the bodies were found in a unit on the third floor.
People living in the building said they believe the three individuals may have passed away at least few days ago, as they described a smell coming from the third floor.
No further information was available as Chicago police continue to investigate.
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