Police said the woman was found unresponsive in the Roscoe Village neighborhood's 3200-block of North Damen Avenue around 3:15 p.m.
She was taken to Illinois Masonic Hospital, where she was pronounced dead, police said.
The Cook County Medical Examiner's Office identified her as 42-year-old Crystal Max. How she died was not immediately clear.
Area Three detectives are investigating.
Authorities did not immediately provide further information.
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