Update: The fire is now 100 percent contained and all structures are secure, according to Melissa Yunas, Florida Forest Service spokeswoman.
Previously: A 10-acre brush fire Wednesday grew to 75 acres in northern St. Lucie County and several homes were evacuated, officials said.
Officials also have closed Indrio Road between Kings Highway and U.S. 1, according to the Sheriff's Office.
St. Lucie County Fire District crews about 1:30 p.m. were called to the fire in the 5200 block of Tree Top Trail, which is north of Indrio Road and west of U.S. 1.
"Homes are being threatened," said Catherine Chaney, St. Lucie County Fire District spokeswoman. "We've got engines sitting by homes to protect them."
Chaney said some residents in the area are being evacuated, while Melissa Yunas, public information officer with the Florida Forest Service, said via Twitter that the fire jumped a road and had grown to 75 acres.
"Deputies are going door to door telling people they need to leave their homes for their own safety in the area north of Indrio Road, between U.S.1 and Kings Highway," Sheriff Mascara said.
FFS say that Holiday Pines is separated from fire by a canal and that those homes are safe.
Indrio Road is closed between Kings Highway and North U.S.1. Motorists are asked to find alternate routes.
FFS notes the main area of concern is between Tree Top and Slash Pine roads, saying, "These homes have defensible space."