On October 5, 1995, approximately 1730 Pacific daylight time, a Piper PA-28-235, N8845W, impacted a tree during an attempted forced landing about one-quarter mile south of Mulino Airport, Mulino, Oregon. The certified flight instructor and the private pilot both received serious injuries, and the aircraft sustained substantial damage. The local instructional flight, which had been in the air approximately one hour, was being operated in visual meteorological conditions. No flight plan had been filed, and there was no report of an ELT activation. According to the private pilot, who was the owner of the aircraft, the engine suddenly lost power while he was descending at less than cruise power. The power loss occured about five miles south of Mulino, and both pilots agreed they should try to glide to the airport at Mulino. While gliding toward Mulino, they unsuccessfully attempted to restart the aircraft's engine. As they neared Mulino Airport, they realized they did not have sufficient altitude to reach the airport, and therefore decided to attempt a landing in a field short of the airport. While attempting the emergency landing, the aircraft collided with a tree at the edge of the field. At the time of the accident, the nearest reported temperature and dew-point data was taken at Portland International Airport, about 40 miles north of Mulino. The temperature recorded at that time was 69 degrees fahrenheit, and the dew point was 44 degrees. According to the Carburetor Icing Probability Chart (DOT/FAA/CT- 82/44), the descent was taking place in conditions conducive to carburetor icing at both glide and cruise power (see attached chart). In a post-accident interview, the private pilot/owner said that at the time of the descent, he did not realize the aircraft was in conditions conducive to carburetor icing, and therefore had not applied carburetor heat until after the engine had lost power. Although only residual fuel was found in the tanks at the accident site, the fuel lines had been ruptured by the force of the impact, and the owner produced fuel receipts that showed the aircraft should have had at least an hour of fuel remaining at the time of the accident. After the accident, the engine was subjected to a teardown inspection, and no evidence of anomalies or malfunction was found.