On August 17, 1993, about 0910 central daylight time, a Piper PA- 28-140 airplane, N4477X, was destroyed when it collided with terrain near Marshall, Minnesota. The airplane was substantially damaged. The non-instrument rated private pilot and the sole passenger aboard received serious injuries. Instrument meteorological conditions existed in the vicinity of the crash site. The personal flight originated from Luverne, Minnesota, about 0830 without a flight plan and operated under 14 CFR 91. The pilot received a weather briefing prior to departure. His intended destination was Wilmar, Minnesota. The FAA Flight Service Station Specialist the pilot spoke with on the telephone indicated that VFR flight was not recommended along the proposed route of flight. The specialist noted areas of fog, reduced ceilings and visibility, and IFR conditions. According to the pilot's written statement to the NTSB, at the time he departed Luverne, he estimated the cloud ceiling as 500 to 700 feet above the ground. The closer he got to Marshall, the lower the clouds became and the visibility deteriorated. He decided to turn around and return to Luverne, but he inadvertently entered the clouds and became disoriented. When the airplane came out, it was in a nose low attitude. The pilot said he pulled the nose up but still struck the ground.