On August 1, 2015, about 1745 central daylight time, a Cessna 182 airplane, N1685R lost engine power while in the traffic pattern at the Watertown Municipal Airport (KRYV), Watertown, Wisconsin. The airplane impacted trees and was substantially damaged. The private rated pilot was seriously injured. The airplane was registered to and operated by a private individual under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed at the time and no flight plan was filed for the local flight. The pilot reported that he planned on doing some practice pattern work, including some touch-and-goes landings in preparation for a flight review. He added that the preflight and taxi were uneventful, and then he departed. While on the base leg, the engine lost power; he advanced the throttle, mixture, and prop levers full forward, and then turned the auxiliary fuel pump on. The engine did not respond, he was unable to locate an open area for an emergency landing, so he decided to aim for nearby trees to arrest his descent. The pilot reported that the airplane had about 75 gallons of fuel on board. The responding Federal Aviation Administration (FAA) inspectors reported that the airplane came to rest on its right side near a residence. The empennage separated from the fuselage, with heavy damage to the right wing and fuselage. The left wing's fuel bladder appeared intact but absence any fuel, the right wing's bladder tank was torn, and contained about two gallons of fuel. The inspector wasn't able to determine the quantity of fuel that may have leaked out after the fuel system was compromised during the accident. The airplane was recovered, and an engine test run was performed. An external fuel source was connected to the airplane; the engine was then started and run. No abnormalities were noted. At 1755, the automated weather observation facility located at KRYV recorded a temperature of 82 degrees Fahrenheit (F), dew point 60 F. The carburetor icing probability chart included in Federal Aviation Administration Special Airworthiness Information Bulletin No. CE-09-35, Carburetor Icing Prevention, indicated that the airplane was operating in an area that was associated with a serious risk of carburetor ice accumulation at glide power settings.