On September 27, 2002, at approximately 8:30 a.m., the Rhea County, Tennessee 9-1-1 Center began receiving calls about a fire at the Watts Bar Hydroelectric Plant.  The plant, built between 1939-42 and operated by the U.S. Tennessee Valley Authority (TVA), is constructed of steel and concrete, and sits on the Tennessee River midway between Knoxville and Chattanooga.  The dam supplying water to the hydroelectric plant is 112 feet high, and approximately one-half mile long.  The plant has a generating capacity of 175,000 kilowatts.  It supplies power for TVA, and provides back-up power for the Watts Bar Nuclear Power Station located directly south of dam.

At the time of ignition—estimated to be 8:15 a.m.—there were five employees working in the hydroelectric plant control room.  The fire spread rapidly, giving these personnel only four minutes to realize that there was a fire and to escape.  All five were able to evacuate the control building, although each employee suffered smoke inhalation.  There were no injuries.

The first call concerning the fire was made by a water delivery man who was at the control building.  A second call was made from the Watts Bar Lake Resort located down the street from the plant.

The fire began in the vertical cable shaft and spread so rapidly to the control building and burned so intensely that fire suppression personnel were unable to make entry into the building until 9:10 a.m.  The fire self-extinguished due to lack of fuel at some point, although investigators could not determine precisely when this occurred.  The intensity of the heat generated during the fire prevented firefighters from accessing the seat of the fire until 12:17 p.m.  In all, over forty personnel from both volunteer and industrial fire departments responded to the fire.

A multi-agency investigation team lead by the TVA Police began the origin and cause investigation on the following day, September 28th.  Based upon physical evidence, the area of origin was determined to be within a 120-foot vertical cable shaft running from the hydroelectric plant to the control building.  Fire modeling was then used to determine fire development and spread, and to estimate the temperature of the fire.  The hydroelectric plant has remained closed since the fire, at a business loss of approximately $100,000 per day.

Although many people perceive a steel and concrete structure as not being a fire risk, this fire illustrated, once again, that a fire in an electrical system can quickly be life-threatening regardless of the structure type.