After the car hit the bicycle that the 8-year-old was riding, leaving her bleeding and seriously injured, the driver did stop briefly, according to witnesses, but then he kept going."He just takes off without helping her," said Upper Darby police superintendent Michael Chitwood. After the witnesses provided a description of the red Nissan and the last four digits of the license number, Upper Darby police arrested Sukhjinder Singh, 33, of the 7200 block of Walnut Street, and charged him with aggravated assault by motor vehicle and leaving the scene of an accident.