The pilot reported that after overflying the airport, he decided to land on runway 21. He extended the wing flaps to the 25-degree position during the approach to landing. The pilot observed that the wind sock was about halfway extended, and he estimated that the wind was from 270 degrees at 20 knots, with gusts to 25 knots. During the landing flare, the crosswind suddenly decreased in intensity, and the airplane impacted hard onto the runway's surface. Thereafter, the airplane veered right and exited the runway. Inspection of the airframe revealed that the nose wheel and the left main landing gear separated from the airframe, the windshield cracked, and the vertical stabilizer was bent. The pilot did not indicate that he had experienced any mechanical malfunction or abnormality with his airplane prior to the mishap.