At approximately 19:00 mountain time a Cessna 152 crashed into a frozen lake near Spanish Fork. The pilot was seriously injured and the passenger, a prospective purchaser of the airplane, suffered minor injuries. The pilot told investigators the flight was a demo flight for the pilot-rated passenger, who was interested in purchasing the airplane. The two estimated visibility at five miles, but shortly after takeoff, while climbing through 300 feet, the airplane entered a cloud or fog. The owner said the prospective buyer then grabbed the yoke because he thought the airplane was turning. The airplane hit the lake, skidded and fell through the ice. The prospective buyer told rescuers, All of a sudden, we couldnt see the lights on the ground anymore. We were disoriented. [The pilot] thought we should descend a little. Thats what we were doing when we hit the lake. We didnt really see it coming. The passenger helped the pilot out of the airplane, where he clung to a wing while the passenger walked across the lake to the Provo Airport about two miles away. The pilot was rescued about four hours after the crash. Neither pilot was instrument rated.