On July 11, 1999, at 1311 Eastern Daylight Time, a homebuilt Pitts S-1S, N2118, was destroyed when it collided with trees while maneuvering at Norwalk-Huron County Airport (OH21), Norwalk, Ohio. The certificated commercial pilot was fatally injured. Visual meteorological conditions prevailed at the time of the accident. No flight plan was filed for the local flight, which was conducted under 14 CFR Part 91. A witness, who was also an aircraft mechanic with a major airline, stated that the pilot started up the airplane, taxied it to the east end of the airport, and performed an engine check. A short time later, the airplane took off east to west, then turned left, and circled the airport. The witness then saw the airplane flying toward the west, over the ramp, and between two rows of "T"- hangars. The airplane rolled inverted "so the family could wave," then quickly returned to a normal, "upright" position. The airplane passed over the pilot's hangar, then over the grass at the end of the ramp. It banked to the right, appeared to be leveling its wings, then struck trees. The witness did not hear any strange engine noises, or notice anything "visibly wrong" with the airplane prior to its impact with trees. According to an Ohio State Police report, the airplane was flying parallel to Runway 28 at a low altitude. "The pilot rolled inverted, rolled back to wings level, and started a turn to the north." The airplane then struck tree tops with the right lower wingtip and right main landing gear. It impacted the ground, and was destroyed by fire. The report also stated that the first possible tree strike was in a 74-foot tree, and that the wreckage path continued along a northerly track for about 400 feet. An autopsy was performed on the pilot's remains by the Cuyahoga County, Ohio, Coroner's Office, and toxicological testing was performed by the Federal Aviation Administration Toxicology and Accident Research Laboratory, Oklahoma City, Oklahoma. According to 49 CFR Part 91, Paragraph 91.303: "No person may operate an aircraft in aerobatic flight...(e) Below an altitude of 1,500 feet above the surface...."