LOS ANGELES (AP) - Wind-driven brush fires scorched nearly 2,500 acres north of Los Angeles on Wednesday, killing thousands of chickens at a farm while destroying at least one home and threatening others. A mandatory evacuation was ordered in Box Canyon and a freeway was closed as the blaze hopscotched the roadway and burned at the west end of the San Fernando Valley. Los Angeles County Fire Department spokesman Ron Haralson said more than 700 firefighters were on the scene. One firefighter was struck on the head by a 40-pound boulder and was taken to a hospital for treatment, Capt....