The pilot reported that following a local flight, the approach to landing and touchdown were normal, however, as he applied wheel brakes, the airplane veered to the right. He attempted to correct with left rudder and brake application but was unable to stop the right veer. Subsequently, the airplane exited the runway to the right and impacted a drainage ditch about 175 ft from the runway’s edge, which resulted in substantial damage to the fuselage and engine mounts. The pilot reported that this was the first landing of the flight, and no anomalies were noted with the brakes or flight controls prior to the landing. He recalled that during the runway excursion, shortly before impacting the ditch, the airplane straightened out and stopped the right turn. Shortly after the accident, the wings were removed for recovery which prevented the investigation from determining whether air was present in the brake lines. Photographs of the main landing gear wheels, brakes, and brake lines revealed no evidence of catastrophic mechanical failures or evidence that brake lines had become disconnected. Review of maintenance records found no evidence of recent brake work, and the endorsements showed that the brake fluid reservoir was serviced routinely. The operator and pilot both submitted a National Transportation Safety Board Aircraft Accident Incident Report (6120.1) and neither party reported that there were mechanical malfunctions or failures with the airplane. About the time of the accident, the automated weather observing system reported wind 220° at 9 knots, gusting to 15 knots, which was a direct crosswind for the landing runway 13. It is likely that the airplane encountered a crosswind gust during the landing roll, which resulted in the airplane veering right toward the direction of the crosswind. This conclusion is further supported by the pilot’s report that the airplane straightened out, once the crosswind became a headwind, shortly before its collision with the ditch.