The pilot reported that, during the landing roll, the tailwheel equipped airplane exited the runway to the left, struck a runway light and impacted a ditch. The left main landing gear separated from the airplane and the airplane came to rest nose down. The airplane sustained substantial damage to the left lower fuselage and left wing. The pilot added that while he was at the departure airport prior to the flight, due to jet blast, he was blown off a ladder during the preflight inspection and that the airplane's tail section was "picked" up and slammed several times onto the ground. He examined the airplane and did not find any anomalies. During takeoff, the pilot did not report any control issues or anomalies but during the flight to the accident airport, he felt the airplane was out of trim. The Federal Aviation Administration (FAA) inspector reported that, during a postaccident examination, he was not able to determine if the damage to the tailwheel was sustained prior to the accident and not caused by the airplane's impact of the ditch. The pilot did not submit the NTSB Form 6120.1 Pilot/Operator Aircraft Accident/Incident Report.