At about 10:47 eastern time, a Piper PA-24-250 lost power and was damaged in a forced landing 5 miles southwest of Immokalee Airport. The instructor sustained serious injuries and the private-rated student sustained minor injuries. The flight had originated about 30 minutes earlier from Naples, Fla. The engine quit at 1,200 feet and the instructor switched from the right to the left fuel tank but the engine did not restart. Investigation of the wreckage revealed no visible fuel in the right main fuel tank; the fuel selector was found positioned to the right main fuel tank. The remaining tanks were nearly full.