Story update Wednesday 11 a.m.:
Cocke County officials told WBIR 10News on Wednesday that several fires along I-40 over the weekend have been ruled accidental and were not intentionally set, as officials originally believed.
The Cocke County Sheriff's Department said its investigation found a blown out truck tire was to blame for the four separate fires.
Sheriff Armando Fontes told WBIR 10News that there was no evidence of any accelerants at the scene but investigators did find pieces of truck tire near each of the fires.
He said it appears a large truck blew a tire, throwing hot chunks of tire into the dry grass area alongside the road. Fontes said it's possible for the steel belts in tires to get hot enough to ignite grass if it is very dry.
(WBIR - Newport) Traffic on I-40 in Cocke County slowed down Sunday afternoon as crews worked to put out what officials said were 8 to 10 intentionally set fires stretching along the interstate.
Cocke County EMA Director Patrick Sheldon told WBIR 10News someone intentionally set multiple fires along several miles of I-40.
Cocke County Fire Chief William Smallwood said crews got the call around 1:30 p.m. Sunday. He said the fires, which burned two acres, are being classified as "suspicious."
Fire crews from Cocke County, Newport, Cosby and the State Department of Forestry responded to the scene and put out all the fires around 3 p.m. Sunday. Smallwood said the fires could have threatened several homes if they hadn't responded so quickly.
Chief Smallwood said the highway never closed but westbound traffic did slow down because of the fires between the 439 and 432 exits.
The Cocke County Sheriff's Department is currently investigating the incident to determine whether or not it was arson.