On March 14, 1999, about 1828 Alaska standard time, a wheel equipped Cessna 180G airplane, N4721U, sustained substantial damage during an emergency landing at the Fairbanks International Airport, Fairbanks, Alaska. The airplane was being operated as a visual flight rules (VFR) local area personal flight when the accident occurred. The airplane was registered to, and operated by, the pilot. The certificated commercial pilot, the sole occupant, was not injured. Visual meteorological conditions prevailed. The flight originated at the Fairbanks Airport at 1825. During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), on March 15, 1999, at 1115, the pilot reported that after departure, he reduced engine power to level the airplane at 1,500 feet, which is the airport traffic pattern altitude. The engine began to run rough, and he began an emergency landing approach to the ski strip, runway 01 at the Fairbanks airport. The ski strip, 01/19, is a gravel surface runway 3,978 feet long and 75 feet wide, and is oriented on the same magnetic heading as runway 01R/19L. There is no lateral displacement between the two runways. The departure end of the ski strip 01 is displaced directly south of the approach end of runway 01R about 650 feet, and is intersected by taxiway B. The pilot said the engine roughness diminished, and he was cleared to land on runway 01R. The pilot said the engine then quit. The airplane touched down in an area of snow between the end of the ski strip 01, and the approach end of runway 01R. The airplane then nosed over, and received damage to the vertical stabilizer, the rudder, and the left wing lift strut. A Federal Aviation Administration (FAA) airworthiness inspector with the Fairbanks Flight Standards District Office (FSDO) examined the airplane on March 28, 1999, and interviewed the pilot. The inspector reported the pilot pushed the airplane out of a hanger, and sumped the wing fuel tanks. The airplane remained outside, and the ambient temperature warmed throughout the day. The pilot did not re-sump the airplane before departing. The inspector's examination of the airplane revealed a longitudinal wrinkle in the left wing fuel bladder. The wrinkle was positioned near the wing sump drain. The inspector also found about 3 ounces of water in the airframe gascolator.