The single-engined airplane was operating on an IFR flight plan and climbing through clouds shortly after takeoff. A witness heard an airplane's engine power surging and observed a bright flash at ground level shortly afterwards. Another witness observed the airplane descending and flying past him just before seeing a bright flash and hearing the crash. The airplane struck an electrical powerline and tree before colliding with the ground and sliding to a stop. An on-scene investigation revealed water in the carburetor float and accelerator pump chambers. The commutator of the turn and slip indicator's electric motor was found with a groove worn around it and a black powdery substance permeating the internal mechanism of the instrument. During an interview with the pilot, he stated that he had taken a fuel sample from each fuel sump on the airplane during his pre-flight walk around inspection. The pilot was unable to recall the events which took place after entering the clouds.