INDIAN RIVER COUNTY — A massive brush fire that started near the Spanish Lakes development in St. Lucie County has crossed into Indian River County, Fire Chief Brian Nolan said Monday.The blaze estimated to already have consumed as much as 100 acres crossed into Indian River County near 6th Avenue and 25th Street SW. In all, five fire engines are at the scene along with several brush fire units working with St. Lucie County and Division of Forestry fire fighters.Nolan said no structures in Indian River County were in immediate danger and there were no evacuation orders in effect. Some homes in Spanish Lakes have received evacuation orders.This story will be updated with more information as it becomes available.