On July 1, 2019, about 1155 central daylight time, a Beech A23 airplane, N3598R, experienced a hard landing on a road following a loss of engine power about 5 miles east of the Ft. Smith Regional Airport (FSM), Ft. Smith, Arkansas. The flight instructor and student pilot were not injured. The airplane sustained substantial damage. The airplane was registered to BAP Group LLC and operated by Southern Eagle Flight School as a Title 14 Code of Federal Regulations Part 91 instructional flight. Visual meteorological conditions prevailed at the time of the accident, and the flight was not operated on a flight plan. The local flight originated from FSM about 1030. The flight instructor reported that the purpose of the flight was to evaluate the skills and proficiency of a prospective student. After takeoff, the student pilot completed some work in the airport traffic pattern and then they proceeded to the local practice area. While returning to the airport, the instructor switched fuel tanks and about one minute later the engine lost power. He took control of the airplane and set up for a forced landing to a road. The airplane touched down hard, slid off the road and into an adjacent ditch. The nose and right main landing gears collapsed, and the engine mount and firewall were damaged. The student pilot stated that after takeoff they proceeded to the practice area and completed some private pilot maneuvers. While returning to the airport, the flight instructor changed fuel tanks since they had been drawing from one tank for the entire flight. She did not recall which tank was selected. About 5 minutes later, the engine started to "sputter" and lost power. The instructor took control of the airplane. She noted that the instructor verified the fuel selector position but did not recall him resetting the fuel selector back to the original tank at that time. Airplane recovery personnel reported about 15 gallons of fuel was drained from the left-wing fuel tank and about 1/4 gallon was drained from the right fuel tank. The fuel tanks appeared to be intact and no fuel leakage was observed. An engine run was conducted under oversight of a Federal Aviation Administration inspector. The engine started and ran normally on both the left and the right fuel selector positions from an external fuel supply. The electric fuel boost pump was used during the engine start; however, after starting the boost pump was turned off and the engine run was conducted using only the engine driven fuel pump. A magneto check revealed no anomalies. A representative of the flight school reported that the airplane had been flown about 1-1/2 hours since it was topped off. The airplane was not fueled before the accident flight. He stated that the fuel level in the right tank was slightly below one-half full. He did not check the fuel level in the left tank; however, he observed the flight instructor conduct a complete preflight inspection. He noted that the airplane fuel selector incorporated left, right, and off positions. Utilizing fuel from both tanks simultaneously was not an option; there was no both setting on the selector. The flight instructor stated that he visually checked the fuel levels before the flight and estimated about 35 gallons were on-board, which amounted to about 3-1/2 hours flight time. He added that the fuel gauges indicated full and the fuel samples taken during the preflight inspection were unremarkable.