The crash occurred at about 7:42 a.m. in the 1700-block of West 69th Street.
Police said a six-year-old girl and a 15-year-old girl were in a crosswalk when they were struck by a white SUV.
Both girls were transported to Comer Children's Hospital, with the six-year-old in critical condition and the 15-year-old in serious condition.
No other injuries were reported. The Major Accidents Investigations Unit is investigating.
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