Only a smoking pile of debris remained Friday afternoon of a vacant building on West Depot Street gutted by flames in a morning blaze.

The cause of the fire at 306-308 W. Depot St. remains under investigation, Greeneville Fire Marshal Alan Shipley said Friday afternoon.

It is known that a man spent the night in the building, which is at least 100 years old. The man and others were questioned by Shipley and Greeneville police, but no charges had been filed as of Friday night.

"It's going to be under investigation, We still have some interviews to do," Shipley said.

"We spoke with him, and there were some things we wanted to verify. We will be able to contact him if there are further things to verify."

No injuries were reported.

The fire burned through the building's roof. Because of the unsafe condition of the front and rear walls, fire investigators could not enter. The walls were torn down Friday afternoon with a pair of track hoes.

Aerial photos taken from a utility company bucket truck may help investigators determine the fire's point of origin, Shipley said.

The fire was called in at 9:03 a.m. Friday, according to county 911 Dispatch. By the time Greeneville firefighters arrived a short time later, the brick two-story building was engulfed in flames and dark smoke.

The blaze destroyed the building, which most recently housed George's Exterminating Co. and Craven Tattoo & Body Piercing.

Firefighters from all four Greeneville stations fought the blaze.

They were able to save the adjacent red-brick building at 310 W. Depot St., where the former Depot Star Grill was located. A brick wall separated that building from the one that burned.

Shipley said the building was intact, but smoke from the fire permeated its interior.

"Those buildings are old. I feel that it had great potential to spread to nearby exposures, and we were able to keep it off of those," fire Capt. John Craft, incident commander, said after the fire was brought under control.

"It was heavily involved when we got here," Craft said. "We had heavy smoke in the tattoo parlor on the second floor, and we had fire visible. Most of the fire was on the back side."

Because of the fire's intensity, "We did not enter the building whatsoever," Craft said.

"It took about an hour to get it under control," he said.

Dark smoke was visible across the downtown area while the fire was raging. Shipley said that a tar membrane roof under a more recent metal roof was the likely cause.

Fire Chief Mark Foulks said at the scene that an investigation into the cause is just beginning.

"We do think we may have had some unauthorized persons inside the building," he said.

No damage estimates were available Friday. Shipley said that at least half of the property is owned by American Patriot Bank.

Electricity was not turned on in the building.

Any time people use methods other than conventional utilities to generate heat, "it raises a concern to us here," Foulks said.

Firefighters were also able to prevent damage to the three-story brick building at the corner of West Depot and South Cutler streets.

A narrow alley separates the former BF Goodrich Car Care Center building from the structure that burned Friday morning.

David Kinser, son of property owner Margaret Kinser, inspected the building as firefighters mopped up hot spots next door.

"It's in good shape," he said.

David Kinser had praise for the work of the Greeneville Fire Department.

"They're magnificent. Any time you've got a group of people that act in a professional manner and save property damage, you've really accomplished something," he said.

Capt. Bill Teague was off-duty but was called in to help supervise the firefighting efforts.

"This building is 100 years old at least. The fire just travels through that old timber, and that's pretty much kindling, as old as it is,," he said. "It's just not safe to make entrance in it."

Insurance investigators may lend a hand beginning Monday, Shipley said.

"I may call the state and let them come in," he said.

Greene County-Greeneville Emergency Medical Services assisted at the fire scene.

Power was cut to the immediate area of the fire by Greeneville Power & Light System. Atmos Energy employees were on scene.

The Greene County chapter of the American Red Cross also responded, setting up a tent and providing drinks and food to emergency workers.