Police say the girl was a student of Chamberlain High School and she was crossing Busch Boulevard at 7:15 a.m. and was not in a crosswalk. The accident occurred about two blocks west of North Boulevard.
At this time, the westbound lanes of Busch Boulevard are closed. Eastbound lanes are open but moving slowly due to police activity.
Police say this case is not a hit and run and the driver is with police at this time.
No other information was released.