More than 6,000 people within a one-mile radius of the Winston Weaver Co. fertilizer plant in Winston-Salem, NC were ordered to evacuate Monday night after a massive fire ignited in the facility.

“Don’t wait for something to happen. Something has happened. Now is the time to get out,” Winston-Salem Fire Chief Trey Mayo said in a tweet.

Crews were called to the Cherry Street factory around 7 p.m. Winston-Salem Mayor Allen Joines told NBC News affiliate WXII that Winston Weaver’s plant has 10 times more ammonium nitrate on site than was stored at West Fertilizer Co.’s West Texas plant when it exploded and caught on fire in 2013. Winston-Salem Fire said in an account by WFMY that the structure was holding 300 to 600 tons of ammonium nitrate when the blaze ignited. Fox News station WGHP said 5,000 tons of finished fertilizer was also stored on scene.

The fire department said in coverage by CBS News that the large amount of the solid crystalline chemical compound at the Winston-Salem facility creates a “potential for explosion.”

Drone footage shared by the fire department shows a large volume of smoke over the facility. As of Tuesday afternoon, crews remained on scene waiting for the fire to burn through the available fuel, WGHP said.

A post on the City of Winston-Salem’s Facebook page Tuesday cautioned owners of businesses within a mile of the facility that access to the area will probably be restricted until the scene is deemed safe.

“A smoke plume from the fire will continue to drive southwest throughout the day Tuesday and is anticipated to impact local air quality across an area to the northwest of downtown Winston-Salem near Wake Forest University,” The Forsyth County Office of Environmental Assistance and Protection (FCEAP) said in a statement posted to Facebook. “FCEAP recommends avoiding outdoor activity in and near the smoke plume, especially children and adults with respiratory illness and/or asthma.”

Winston Weaver manufactures specialty fertilizers, pelleted limestone, and all-purpose plant food, information on its website states. The Winston-Salem plant started operations in January 1940.