On April 21, 1999, about 1400 Eastern Daylight Time, a Cessna 152, N48005, was substantially damaged during a forced landing near Wall, New Jersey. The certified flight instructor (CFI) and passenger were not injured. Visual meteorological conditions prevailed, and no flight plan was filed for the instructional flight conducted under 14 CFR Part 91. The CFI stated that the flight was intended to introduce the passenger (prospective student) to flight training. During the preflight of the airplane, he visually checked the fuel tanks, and confirmed that reading with the cockpit gauges. The flight departed Allaire Airport, Farmingdale, New Jersey, about 1300. After about 30 minutes of flight, the engine began to run rough. The CFI applied carburetor heat for about 90 seconds, and the engine appeared to run normal again. Approximately 10 minutes later, the engine began to run rough again, and the CFI decided to return to the airport. The fuel gauges were visually checked again by the CFI, and indicated "adequate fuel" in both tanks. About 1 mile from the runway, the engine quit running, and the airplane began to descend. The CFI turned the airplane towards an open grass field, and executed a forced landing. The airplane hit trees located 50 feet prior to the grass field, continued to descend, and impacted the ground. The airplane came to rest on its left side, nose high, wedged between budding trees. Examination of the wreckage by a Federal Aviation Administration Inspector revealed no signs of fuel stains on the airframe or engine. Maintenance personnel removed a jar containing 4 ounces of clear liquid that had a blue tint similar to aviation low lead fuel, from the fuel strainer. The sample did not reveal any signs of water. No fuel was observed in the wing tanks when the wings were removed from the airframe. A review of fuel records indicated that the airplane had been fueled on April 19, 1999, with 12.4 gallons of 100 low lead aviation gasoline, filling the 26-gallon fuel tanks to capacity. A review of invoices provided by the operator of the airplane indicated that the airplane had been flown a total of 4 times prior to the accident flight. The total Hobbs meter flight time for the flights was 5.5 hours.