By Dan Whitcomb LOS ANGELES (Reuters) - A 63-year-old woman was fatally mauled by a pack of pit bulls while walking near her home in Southern California on Thursday and authorities were still searching for the dogs as darkness fell, law enforcement officials said. A driver called police Thursday morning to report that four dogs were mauling the woman by the side of a road in the small unincorporated community of Littlerock, near Palmdale, Los Angeles County Sheriff's Captain Mike Parker said.