On August 5, 2016, about 1450 central daylight time, an Aero Commander S2R airplane, N5599X, made a forced landing to a swampy field following a total loss of engine power. The commercial pilot was not injured and the airplane sustained substantial damage. The airplane was registered to and operated by Lakeview Aviation Inc., under the provisions of 14 Code of Federal Regulations Part 137 as an aerial application flight. Visual meteorological conditions prevailed at the time of the accident and no flight plan had been filed. The local flight departed from a private grass strip at an unknown time. The pilot reported that prior to the departure the airplane was loaded with 300 gallons of water and spray solution and an undetermined amount of fuel. After departure, the pilot flew 5 miles south of the private strip and proceeded to spray a 130 acre field. When the spray solution was depleted, the pilot flew back toward the private strip and noticed the fuel quantity indicators showed 1/4 remaining in the right tank and 1/8 remaining in the left tank. About 1.5 miles southeast of the private strip and about 400 ft above ground level the engine "sputtered" and experienced a loss of power. He made a forced landing to a field and the airplane nosed over when it entered a swampy area. The pilot noted that there were no mechanical malfunctions or failures with the airplane that would have precluded normal operation. According to the pilot's statement, the person who fueled the airplane stated that before the fueling process began, the fuel indicators were reading ½ full in the right tank and ¼ full in the left tank. The fueler only added fuel to the left tank, but he could not remember the exact amount added and assumed the fuel system would equalize the amount both tanks. The pilot stated the capacity of each fuel tank is 53 gallons and if the fueler only added fuel to the left tank then he couldn't have added more than 40 gallons. The pilot did not visually check the fuel tanks before departure for the flight that reportedly lasted over an hour. The responding Federal Aviation Administration (FAA) inspector examined the engine and found no presence of fuel in the fuel lines to the engine. The fuel filler caps were removed and no fuel was present. The propeller blades did not sustain any leading edge damage or chordwise scratches. The inspector noted that the airplane sustained substantial damage to the left wing and fuselage.