KNOXVILLE, Tenn. (WATE) —  A firefighter helping in Wears Valley on Wednesday captured intense video showing how strong winds affected efforts to contain the wildfire on Hatcher Mountain.

Tom Lucas is a firefighter with Sevierville Fire Department who volunteers with Walden’s Creek Volunteer Fire Department.

“There were many moments of extreme intensity due to high levels of changing wind speeds and conditions.” said Lucas, “One minute, things were pretty calm and out of nowhere, wind driven fire would make you seek shelter.”

The wildfire spread quickly. As of Thursday, 3,700 acres have burned and more than 100 structures have been damaged. The blaze is about 30% contained, fire officials said. An evacuation was ordered for parts of Wears Valley, Walden’s Creek and near Pigeon Forge.

The video shows strong wind pushing the fire across a roadway as sparks and flames spiral in the air.

“All of the firefighters had to be very vigilant of their surroundings and keep their head on a swivel. Things would change in a moment’s notice,” he said.