WAYCROSS, Ga. -- Firefighters appeared to be losing ground against a massive wildfire that has been burning near Waycross for 11 days.

Fire officials said the largest of six fires was flaring up, and another smaller fire near Nahunta was rekindled on Thursday.

Officials made a decision Thursday evening to cancel school in Ware and Brantley counties for Friday. Pierce County schools will hold classes Friday but they will be delayed by an hour.

The largest fire has grown to more than 61,000 acres -- that's about 95 square miles -- and according to officials has potential to get worse and spur more evacuations.

At one point, the blaze was 75 percent contained, but that number is down to 50 percent.

Hundreds of residents were told to leave their homes as one wildfire rekindled and destroyed at least four houses and another threatened to jump a highway, authorities said.

"Literally, I got a phone call telling me to evacuate and go ahead and get out. We already had stuff packed and ready to go and started moving it to the car, and then another sheriff's deputy came in the yard and said, 'You don't have time. You've got to go ahead and go, now,'" said Misty Carter.

Carter, Jason Thorton and their 1-year-old son had to leave the home in an instant, with the fire so close they didn't have time to grab clothing, medicine or anything with sentimental value.

"We know we will probably have nothing left after tonight," Carter said.

The family, along with others in the community attended the informational meeting held at Ware County Middle School, which is also the site where evacuees can seek shelter.

"We are seeing growth with the fire. Actually, the fire is roughly 60,000 acres right now and we're going to see it continue to expand if we can't hold our lines because weather is just going to just get worse. Today was just a taste of what we're going to experience tomorrow," said Robin Cole of the Georgia Forestry Commission.

A fire near Nahunta, east of Waycross, that firefighters said they had contained last week began raging again Thursday afternoon, 911 dispatcher Elaine Wilson said.

She did not know exactly how many people had to leave their homes but said it was hundreds. She was also unsure how extensive the fire was but said it spread about four miles along U.S. Highway 301.

Ware County sheriff's deputies visited about 100 homes in and near Astoria, a tiny community three miles southeast of Waycross, asking people to leave as a wildfire in the Okefenokee Swamp approached. Most had just returned home after evacuating for several hours Wednesday.

"My nerves just can't take it anymore," said Mary Howell, 51, as she packed stacks of framed family photos in the trunk of her Lincoln Towncar for the second time in two days. "I haven't slept in a week since this stuff started."

In the past 11 days, wildfires have blackened nearly 100 square miles of forest and swamp parched by drought. Officials said a total of 18 homes have been destroyed.

Emergency officials closed 16 miles of U.S. Highway 1 and railroad tracks running alongside near the Okefenokee Swamp.

The wind blew hot embers from the swamp across the highway, igniting small spot fires near the Georgia Forestry Commission district office that fire officials had been using as a command center.

Firefighters contained the small fires quickly, but the command center had to be evacuated, said Eric Mosley, a spokesman for the Georgia Forestry Commission.

Meanwhile, firefighters used bulldozers to widen fire breaks plowed along both sides of U.S. 1, while airplanes sprayed fire-retardant foam to try to stop the blaze from advancing.

Winds out of the southwest were pushing the fire to the north Thursday night. Channel 4's Jennifer Bauer reported 25 mph winds were expected for Friday, increasing chances the fire would spread across the four-lane, divided highway that connects Waycross with Jacksonville, Fla.

If the blaze crosses the highway, firefighters said it could threaten two towns. "All there is between U.S. 1 and Nahunta and Hoboken is just timber, tons and tons of timber with unlimited fuel," Mosley said.

About 1,000 people were forced to evacuate their homes near Waycross last week, and most have not been allowed to return. An additional 5,000 people had been urged to voluntarily evacuate because of health risks posed by heavy smoke.