A 9-year-old girl died Sunday after a pit bull attacked her while she played with friends in a Long Island backyard, authorities said. Nassau County police officers responded to a 911 call at a Holland Avenue house in Elmont at around 10:30 a.m. and found the dog attacking the girl. When one of the officers entered the yard from the house, the dog charged at the officer, who shot and killed the animal, said Detective Michael Bitsko. "It was a violent attack," he said. "They had to put the dog down." The girl's identity hasn't been disclosed by police. There...