The pilot reported that he took off in dark night conditions and was using flight following. When he arrived at the destination airport, he activated the runway lights while entering the downwind leg. While on final approach, the runway lights suddenly turned off, so he aborted the landing. The pilot again activated the runway lights on the downwind leg, but this time he flew a short base leg to final. The airplane was at a lower altitude for the approach and suddenly entered a heavy band of fog. The left wing subsequently hit the soft dirt, cartwheeled, and then came to rest inverted about 1/4 mile short of the runway. Postaccident examination revealed substantial damage to the left wing and fuselage. The weather conditions reported at the airport, about the time of the accident, were calm wind, visibility 4 statute miles, moderate mist, clouds scattered 100 ft, temperature 15°C, dew point 15°C, and an altimeter setting 29.24 inches of mercury. The pilot did not submit the National Transportation Safety Board Pilot/Operator Aircraft Accident /Incident Report Form 6120.1.