(CNN) -- South Carolina Gov. Mark Sanford declared a state of emergency Thursday for a coastal county where a wildfire has consumed thousands of acres and destroyed dozens of homes.



Scott Vereen sprays water on his family's home Thursday near Conway, South Carolina.



"This has already proved to be a devastating event for Horry County, and it isn't over," Sanford said in a written statement.



The county includes some of the state's most popular tourist spots, including the Myrtle Beach area.



By late afternoon, however, officials in North Myrtle Beach said the fire there was mostly contained.



"The fire is very contained on our end right now," said the city's director of public safety, William Bailey. "We have hot spots. I would say we're about 75 to 80 percent [contained]."



But as he gestured toward the dark clouds behind him, he told people who had been evacuated: "As you see with the smoke and activity behind us, we still got some issues that we're concerned about. We're doing everything we can to get you home."



Authorities began alerting people in the city's Barefoot Resort area early Thursday after the fire jumped a highway and began consuming some houses.



As of about 6 p.m. ET Thursday, the fire had consumed 15,500 acres, destroyed 69 homes and damaged 100 others, according to the Horry County Emergency Operations Center. While no fatalities or injuries were reported, some 2,500 people have been evacuated, officials said. About 440 people were in two shelters at the House of Blues and at the North Myrtle Beach Aquatic Center, the operations center said.



Both the Barefoot Resort and the Pelican Bay subdivisions had been evacuated. In addition, three schools were evacuated because of heavy smoke.



Eight vehicles had been destroyed as of Thursday afternoon, said Mayor Marilyn Hatley.  Watch footage of coastal areas in flames »



Bailey said authorities were hopeful the weather would continue to cooperate. Low humidity had persisted for most of the day.



"We have the resources, we just need to get a weather break," he said.



Authorities said the fire has been unpredictable. "When we got our last report [Wednesday], we had no idea that it would be crossing over into the Barefoot Resort area," Hatley said at the morning news conference. "The fire kind of created its own weather, and it just started the wind spinning."



Nick Gentile, 64, told The Myrtle Beach Sun News that he left his Barefoot Resort home around 2 a.m. Thursday. "They came around with a police car with a loudspeaker," he told the newspaper, still wearing his blue-plaid pajamas. "You always read about stuff like this, but you never know when you are going to be in it."



Helicopters were conducting water drops over portions of the area, Hatley said.



The National Weather Service issued a dense smoke advisory for the county until 3 a.m. Friday. Thick plumes billowed high above buildings, prompting North Myrtle Beach school officials to close school Thursday, CNN affiliate WPDE-TV reported.



Officials have not determined a cause for the fire, which began about noon Wednesday in Conway.



CNN's Samuel Gardner contributed to this report.
What did Sanford declare? where No injuries are reported? what Area is home to popular tourist spots? Who declared a state of emergency?
South Horry County the Myrtle Beach Carolina Gov. Mark Sanford
question: What did Sanford declare?, answer: South | question: where No injuries are reported?, answer: Horry County | question: what Area is home to popular tourist spots?, answer: the Myrtle Beach | question: Who declared a state of emergency?, answer: Carolina Gov. Mark Sanford