On September 7, 2015, about 1000 eastern daylight time, an experimental amateur-built Van's RV-6A, N555TN, was substantially damaged during a forced landing in a field after a total loss of engine power in Rome, Georgia. The pilot was seriously injured. Visual meteorological conditions prevailed and no flight plan was filed for the local personal flight, which departed Richard B. Russell Regional Airport (RMG), Rome, Georgia, and was conducted under the provisions of Title 14 Code of Federal Regulations Part 91. According to the pilot, during the preflight inspection he measured the fuel quantity in the right tank as 3 gallons, and the left tank as 6 gallons, using a dip stick. He noted that the fuel was "low, but adequate for 2-3 touch-and-go landings." He recalled using the right fuel tank for taxi operations, and had moved the fuel selector to the left tank just prior to the engine run up, where it remained for the duration of the flight. The pilot reported that after takeoff, he had completed one touch and go landing to runway 7, and remained in a left traffic pattern. As he turned left to the base leg for a second landing, he elected to remain at the traffic pattern altitude of 1,500 feet, extend the base leg beyond the runway centerline, and then turned left to an upwind leg parallel to the runway. He intended to complete another full traffic pattern before landing. As he began a left turn to the crosswind leg about 4.5 miles beyond the runway 25 threshold, the engine lost all power. He then performed a 180-degree left turn toward runway 25. After an unsuccessful attempt to restart the engine, he determined that he would not make the runway, and turned left towards a field for an off-airport landing. Examination of the accident site and airplane by a Federal Aviation Administration inspector revealed that the airplane had come to rest upright in a grass field. The nose and left main landing gear were collapsed. Both wings were bent upward outboard of the flaps. The right side of the empennage displayed compression buckling just aft of the right rear window, and had partially separated from the fuselage on the left side at the same location. The left horizontal stabilizer and elevator were bent down and forward. Flight control continuity was established from the flight control surfaces to the cockpit controls, with some binding noted consistent with impact damage. The spark plugs were removed and appeared normal in color and wear. The left magneto produced spark on all leads. The right magneto was inaccessible and could not be tested. The engine drivetrain was rotated by hand at the propeller, and thumb compression and suction was noted on each cylinder. The fuel tanks remained intact. About 1.5 gallons of fuel was present in the left fuel tank. The right fuel tank was found absent of fuel, and no fuel was present in the fuel strainer. Review of a pilot operating handbook for a similar make and model airplane revealed that each tank held 19 gallons of fuel, with about 1 gallon in each tank unusable.