On October 16, 1998, at 0645 central daylight time, a Cessna 172H airplane, N2513L, was substantially damaged when it impacted terrain during takeoff from the Lake Bonanza Airport, Conroe, Texas. The non-instrument rated private pilot, who was the owner and operator of the airplane, and the pilot-rated passenger sustained minors injuries. Night visual meteorological conditions prevailed and no flight plan was filed for the Title 14 CFR Part 91 personal flight, that was destined for San Angelo, Texas. The flight was originating at the time of the accident. The 1,348 hour pilot reported in the Pilot/Operator Aircraft Accident Report (NTSB Form 6120.1/2) that he positioned the airplane at the approach end of runway 17 for takeoff. Runway 17 is 2,579 feet long, of which the first 100 feet is concrete and the remaining length is turf. The pilot stated that just prior to beginning the takeoff roll all of the windows fogged. The passenger exited the airplane and cleared the outside of the windows, while the pilot cleared the inside of the windows. The pilot initiated a short field take off and the airplane lifted off the ground approximately 1,000 feet down the runway. During the takeoff roll, the windshield and side windows became obscured by condensation (fog), blocking the pilot's view of outside references. The pilot stated that he maintained control of the airplane by referencing the flight instruments. The airplane was approximately 60 feet above ground level when the passenger "excitedly" stated "trees left, trees left!" The pilot mistakenly interpreted the statement of the passenger as "veer left, veer left." The pilot banked the airplane "slightly" to the left and the left wing of the airplane contacted a tree branch which resulted in "spinning the aircraft left and pointing [it] straight down." The airplane came to rest approximately 30 feet east of the extended runway centerline, on its nose in a near vertical attitude, in a wooded area. The pilot stated that at the time of the accident night conditions existed and the skies were clear. At 0753, the Montgomery County Airport, which is located approximately 10 nautical miles east of the accident site, reported that the temperature and dewpoint were 72 degrees. An FAA inspector examined the airplane at the site and reported that the engine firewall was displaced, the nose gear and propeller were bent and both wings were structurally damaged.