A sudden, unexpected burst of high winds caused a controlled burn in the Croatan National Forest to get out of control.

A sudden, unexpected burst of high winds caused a controlled burn in the Croatan National Forest to get out of control and burn 21,000 acres this summer, according to a report on the fire.

The U.S. Forest Service released its “Learning Analysis” of the fire that prompted road closures in the forest and affected the region for weeks with heavy smoke.

The report shows that the controlled burn that began on June 14 to remove undergrowth and improve habitat for the red cockaded woodpecker in 1,567 acres went well at first.

Subsequent burns on June 15 and June 16 also had no issues. However, the report cites a sudden burst of high winds during a 20- to 30-minute window around 2:30 p.m. on June 16 that sent embers across South Little Road outside of the controlled burn area as the reason behind the wildfire.

The report shows that maximum winds had been up to only 15 mph, but that the wind suddenly picked up to 23 mph.

“The winds that kicked up for that half an hour were what we suspect as contributing to us having a spot fire,” Barry Garten, acting district ranger for the Croatan National Forest, said on Thursday.

“We did everything that we possibly could to make sure that everything was in good shape but when the wind comes up like that, a kind of anomaly of a wind that no one saw, it makes it difficult to keep everything in check.”

According to the report, a forest service helicopter spotted the new fire at about 3 p.m. June 16 and estimated its size at 50 to 75 acres. By 6 p.m., it had grown to 235 acres.

Forestry officials opted not to fight the fire through the night of June 16, citing safety concerns, according to the report. By the morning of June 17, the fire had spread to 2,800 acres.

The report lists that the controlled burn created a “smoke screen” that made detecting the wildfire difficult. The report also mentioned the importance of maintaining communication with the National Weather Service about weather conditions during controlled burns.

The report, put together by eight forestry officials that were not directly connected to the fire, mentioned that the preparation, plan and practices established for controlled burns were followed and that officials took appropriate action once the wildfire started.

“The one thing that we learned, if you read through it, is everything that we did was in accordance with our own policies, and that was the one thing that was highlighted to me,” Garten said.

More than 100 employees from the U.S. Forest Service, N.C. Forest Service, U.S. Fish and Wildlife Service, Department of Defense and others helped to fight the fire, which wasn’t contained for another three weeks.

“All of the responders that came to support us when the fire did cross were invaluable in helping us successfully manage the incident,” Garten said. “One thing that does stand out is the hard work, the cooperation, and the coordination with all of them, and the weather service is part of that.”

U.S. Rep. Walter B. Jones, R-N.C., 3rd Dist., had called for an investigation into the fire shortly after it started.

“Federal agencies must be accountable to the taxpayers, and I credit the forest service for asking the tough questions to determine what happened and how to prevent it from happening again,” Jones said in a statement.