On December 1, 1995, at 1130 central standard time, a Bellanca 8KCAB, N53870, was substantially damaged following a collision with trees and terrain during a forced landing attempt near Alexander City, Alabama. The airline transport pilot received minor injuries in the accident. The aircraft was being operated under the provisions of 14 CFR Part 91 by the pilot. Visual meteorological conditions existed at the time, and a visual flight rules flight plan was in effect for the flight. The flight departed Columbus, Georgia, at 1045. The pilot stated that while at cruise flight at 4,500 feet above mean sea level, the aircraft engine began to run roughly, and then stopped producing power. The pilot attempted to execute a forced landing on a roadway, but impacted trees, and the terrain during the approach. Examination of the aircraft engine revealed that the "O" ring and diaphragm in the fuel injector servo were leaking. The leaking servo resulted in a rich fuel/air mixtureand subsequent loss of engine power.