KNOXVILLE, Tenn. (WATE) — The Knoxville Fire Department was at the scene of a working house fire early Wednesday morning in the Fountain City area.

A news release from KFD states that firefighters responded to a call that came in at 4:38 a.m. Another caller advised the fire was located behind her home on Medlin Heights Road, and there was an explosion.

Once crews arrived at the scene, they found the house fully involved and quickly went to work to extinguish the flames.

“However, the heavy volume of fire and the length of time the structure had been burning made it difficult to extinguish the fire quickly,” the KFD news release states.

No one was at home at the time of the fire, and KFD says that as of 6:15 a.m., the residents had not yet been located of notified. The home is a total loss.

One firefighter was evaluated at the scene for a minor injury.

KFD’s Investigations Unit is working to determine the cause of the house fire.

KFD initially said on its social media that the house fire is located in the 5800 block of Fairhill Lane. The agency also shared photos from the scene, showing smoke emerging from the home and flames on the wooden porch.

Editor’s Note: This story has been updated.