A 24-year-old woman was killed after a fatal hit-and-run in Chester, Delaware County, on Tuesday morning, police said. Chester Police are asking for the public's help in locating the driver. The victim, a Boothwyn resident, was walking in the area of 9th and Hayes Streets around 7:30 a.m. The vehicle that hit her was described as a black Nissan sedan, with heavy front-end damage. It was last seen going east on West 9th Street at a high rate of speed.