After a normal parachute drop at 13,000 feet, the pilot initiated a descent. As the airplane descended to 2300 feet, both engines lost power. Unable to restart either engine, the pilot initiated an emergency landing to runway 9 at the departure airport. However, before reaching the runway, the airplane collided with vegetation and the airport perimeter fence. An examination of the airplane failed to disclose a mechanical problem. No usable fuel was found in the fuel system during the postaccident examination.