According to the pilot, the wind was calm at the time of the accident. He entered the traffic pattern on a left base leg at 120 knots with the landing gear extended and flaps extended 20 degrees. He turned onto final approach to runway 36, and when the runway was assured, extended the flaps to 40 degrees and confirmed the landing gears were down and locked. Upon landing, the airplane suddenly pitched nose down and he realized there was a discrepancy with the nose landing gear. He applied full thrust reverse, stopped, and secured the airplane on the runway. Postaccident examination of the airplane by a Federal Aviation Administration (FAA) inspector revealed the nose landing gear was collapsed, the left main landing gear tire was separated from the wheel, and the wheel assembly was separated from the landing gear. Wrinkles in the fuselage skin near the forward pressure bulkhead were noted on both sides of the airplane. Additionally, the left and right upper and lower wing spars were distorted, and the fuel tanks at the wingtips were dislodged and loose from their mountings consistent with substantial damage. The pilot reported to the FAA inspector that he observed no mechanical malfunctions or anomalies with the airplane before the hard landing.