Units of the Greeneville Fire Department were dispatched about 7:20 a.m. today to a report of a possible fire at the Greeneville Dialysis Center on Serral Drive.

Emergency radio transmissions between Greene County 911 and responding fire units indicated that a rear room at the 180 Serral Drive clinic was filling with smoke and that there were patients inside the structure.

GFD Lt. Marty Shelton said after fire units cleared the scene that no smoke had been in the portion of the building where patients were being treated.

He said the patients had been evacuated from the building to the parking lot as a precaution.

Firefighters, Shelton said, determined that the source of the smoke in the rear storage and mechanical room was a malfunctioning, roof-top heating and air-conditioning unit.

Firefighters shut down the malfunctioning unit and cleared smoke from the storage room using large fans.

Normal operations resumed at the dialysis center shortly after 8 a.m., Shelton said.

Fire units left the scene at 8:10 a.m. and returned to their stations.