LYNN-A hit-and-run car accident Thursday on Walnut Street has claimed the life of a dog, police said.Police responded to 390 Walnut St., near Dungeon Avenue, at about 5:15 p.m. on a report that a 15-year-old girl and her 8-year-old black Border Collie named Pepper were hit by a car.The force of the accident threw the dog onto a home’s front lawn, police said. The animal died within 30 minutes of being struck, according to Animal Control Officer Kevin Farnsworth.The car, described by witnesses as a compact blue or silver Toyota kept on driving down Walnut Street toward Dungeon Avenue.The girl was transported to Salem Hospital with minor injuries to her ribs and neck, police said.Anyone who witnessed the accident is urged to call Lynn Police Traffic Investigator John Meaney at 781-477-4379.