The girl, identified by police as Rusroshi Barua, was taken to Elmhurst Hospital, where she was pronounced dead Sunday afternoon.
Barua landed in a backyard about 60 feet below the bathroom window.
Police say she got locked inside with her 2-year-old sister. Police say there were no bars on the window.
The parents could not get in to the bathroom, and then called the super, who knocked the door down. When they got inside, only the 2-year-old was in the bathroom.
The parents looked out of the window, and saw Barua on the ground.
There is no criminality suspected, and the investigation is ongoing.
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