At 1330 eastern time, a Cessna 172N, N737TG, was substantially damaged during landing at the Lake Anna Airport when the airplane departed the side of the runway. The pilot was not injured. The pilot said he departed Fredericksburg, Va., to fly to some nearby airports and return to Fredericksburg. He flew to Tappahannock Airport and then determined that he had time for one more stop. He decided to fly to the Lake Anna Airport. The pilot said a wind gust blew him off the left side of the runway just as he was flaring to land. He blamed the accident on the narrow runway, which is 2,560 feet long and 25 feet wide. He said he had never flown into such a narrow runway before.