On June 5, 1993, at 2145 central daylight time, a Cessna 210L, N2267S, registered to Steven R. Mowery of Clarinda, Iowa, and operated by a private rated pilot, experienced a loss of engine power while in cruise flight and performed a forced landing in a farm field near Indianola, Iowa. The airplane sustained substantial damage, however the pilot and two passengers reported no injuries. The personal 14 CFR Part 91 flight was operating in night VFR conditions. No flight plan was on file. The flight departed Marion, Iowa, at 2020, with the intended destination of Clarinda, Iowa. A post accident examination of the engine revealed that the crankshaft had fractured. Further laboratory examination was conducted by the NTSB Office of Research and Engineering. Their report is an addendum to this report. Their findings did not determine the initiating circumstances leading to the fatigue fracture of the crankshaft.