During a local flight to take pictures of the passenger's house, while making a pass by the house the airplane entered a left turn. The passenger stated that he heard the pilot say "oh no," moments later the airplane impacted the tops of the trees. A witness on the ground stated she heard the airplane fly over and went outside to see it. At that time she heard the top of the trees "pop" and saw the aircraft hit the ground. The pilot reported no preimpact mechanical malfunctions or anomalies that would have precluded normal operation. A subsequent examination by a Federal Aviation Administration inspector did not reveal any evidence of any preimpact failure of malfunction of the airplane, flight control system, or engine. Review of photographic evidence also revealed both wings evenly bent aft indicating the aircraft struck the trees in a level attitude in forward flight.