On June 7, 1998, at 1117 hours Pacific daylight time, a Piper PA-28-181, N84451, operated by Golden State Aviation of San Diego, California, was substantially damaged during a forced landing at El Cajon, California. Neither the instructor pilot nor the two dual student pilots were injured. The aircraft was operating under the provisions of 14 CFR Part 91 and no flight plan was filed. Visual meteorological conditions prevailed for the local instructional flight. The instructor pilot was departing with two beginning student pilots for a local area flight. He stated that during a departure climbout from runway 27L, about 50 to 100 feet agl, the engine quit and he force landed beyond the runway end. According to the Federal Aviation Administration (FAA) inspector on-scene, the fuel sump drain may have been left open during the preflight causing fuel starvation during climb. No other discrepancies were found with the airplane by the inspector. The flight instructor was counseled by the FAA regarding preflight procedures.