On December 13, 1998, at 1130 mountain standard time, a Cessna 182RG, N9854C, sustained substantial damage when it departed the side of the runway during landing roll at Glenwood Springs Municipal Airport, Glenwood Springs, Colorado. The private pilot and his three passengers received serious injuries. The flight was a cross-country flight operating under Title 14 CFR Part 91 from Saint George, Utah, to Glenwood Springs, and a VFR flight plan was filed. Visual meteorological conditions prevailed for this flight which originated approximately one and one half-hours prior to the accident. According to a witness to the accident, the aircraft appeared to be low on final approach to landing and had to add power to make the runway. As the aircraft approached the runway, power appeared to be reduced and the nose dropped. The witness said the aircraft touched down nose wheel first and began to porpoise and oscillate in yaw. She said that it sounded like power was added before the aircraft exited the side of the runway. Witness marks provided evidence that the aircraft departed the side of runway 32 approximately 1,700 feet down the runway from the approach end. It exited the left side of the runway on a heading of 294 degrees. The aircraft crossed approximately 350 feet of dirt and shrubs and collided with a chain link fence. It slid down the fence 50 feet where it collided with a pallet loaded with approximately 2 tons of steel natural gas pipe. The top rail of the chain link fence, a pipe about 2 inches in diameter, penetrated the aircraft. It came through under the instrument panel, and exited out the left rear side window. Examination of the aircraft provided no evidence of structural or system failure or malfunction. According to the pilot's logbook, he had 105 total flight hours with 24 hours in the accident aircraft make and model and 4 hours in the last 90 days in make and model. Weather conditions at the time were reported to be clear skies with light and variable wind at 3 knots.