KNOXVILLE, Tenn. (WATE) — One woman has died after a fire at a residential mobile home early Wednesday, according to Rural Metro Fire-Knox County and the Knox County Sheriff’s Office.

Thursday, the Knox County Sheriff’s Office released that the woman who was killed was Karen Sue Rutledge, 66, of Knoxville.

KCSO also released that fire investigators ruled the cause of the fatal fire as undetermined because of the extensive damage to the home and a lack of physical evidence. Based on witness and family statements, however, investigators believe it is likely that cigarette smoking in the presence of oxygen was a contributing factor.

A news release shared by Rural Metro public information officer Jeff Bagwell on Wednesday states that at around 3 a.m., crews responded to a reported structure fire, with an explosion, in the 5500 block of Fort Sumter Road in North Knox County.

When crews arrived, they found what was described by Bagwell as a single-wide trailer “well involved” with fire and one fatality as a result of the fire. Crews were able to extinguish the fire without impacting any nearby structures.

The Knox County Fire Investigation Unit will handle the investigation, Bagwell said.

KCSO said in an email update that Fort Sumter Road would remain closed for an undetermined amount of time in order to process the scene.

EDITOR’S NOTE: This story has been updated.