According to the pilot, the air was smooth and there were no mechanical malfunctions with the amateur built Lancair IV-P. Upon arrival at his destination airport, he joined the traffic pattern for landing. During the final approach for landing, the airplane touched down about 8 feet prior to the paved runway surface. Both main gear wheels then impacted the edge of the runway pavement, which was approximately 4 inches higher than the surrounding terrain. The right main landing gear wheel separated from the gear leg and the pilot applied "full" left brake and rudder input in an attempt to keep the airplane on the runway centerline. He was unsuccessful, and the airplane began veering to the right. It then departed the right side of the runway, and impacted a ditch which sheared the nose landing gear and collapsed both main landing gear legs. The airplane came to rest approximately 12 feet beyond the ditch after impacting trees, and had sustained substantial damage.