Investigators returned today to the 300 block of West Depot Street, where two separate fires tore through adjoining buildings Friday morning and Sunday night.

Both are considered suspicious, Greeneville Fire Marshal Alan Shipley said today.

A fire Sunday night that heavily damaged a building at 310 W. Depot St. that housed the former Depot Star Grill started on the second floor.

The fire Friday morning destroyed a vacant two-story building next door at 306-308 W. Depot St.

"Yes, it is suspicious," Shipley said. "We've done several interviews, and we've got some more slated for today."

The remainder of the gutted 100-year-old building gutted by fire Friday was razed for the safety of the public.

The unsafe condition of the other structure, a red brick-building at 310 W. Depot St., makes it difficult for fire investigators to gather evidence about the blaze, which was called in at 7:52 p.m. Sunday and burned through the roof.

Members of the Bomb and Arson Investigation Section of the state Division of Fire Prevention will return today to assist local investigators.

Shipley said investigators looked into the 310 W. Depot St. building from above Monday from a Greeneville Department of Public Works bucket truck.

"We took some pictures. We're going to go over those pictures, and we're going to go back to the scene today," Shipley said.

The building is owned by J.T. Long, who sat across the street Monday afternoon and watched the investigation with great interest.

Long said the building is not insured.

"I was going to fix it up," he said.

Long is familiar with reports that someone spent the night in the building at 306-308 W. Depot St. before it caught fire Friday morning.

If the fires are found to be arsons, Long wants those responsible brought to justice.

"He better hope I don't catch him," he said.

Long's building may have to be razed, Greeneville fire Chief Mark Foulks said Monday.

"The condition it is in, it might have to come down," Foulks said.

The unsafe condition of the building presents challenges for investigators seeking clues about the Sunday night fire, Shipley said.

"It's difficult to do when you can't physically go in," he said.

Four state arson investigators will assist in the work today, Shipley said.

A brick wall separated the building that burned Sunday night from the one destroyed by flames Friday.

"According to a statement from [Long, the owner] no one was supposed to be inside the building," Shipley said Monday. "We have not talked to anyone who was in the building."