On June 17, 2024, at 1949 eastern daylight time, a Lockheed 12A airplane, N2072, was substantially damaged when it was involved in an accident near Jackson, Georgia. The commercial pilot and two passengers were seriously injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. According to the pilot, maintenance was performed 10 days before the accident, on June 7, 2024, to replace the right main landing gear strut seals. The maintenance required removal of the right landing gear strut assembly, and the associated brake line was disconnected and capped during the procedure. The pilot reported that, following reinstallation of the strut assembly, the brake lines were reconnected and tightened. On June 10, 2024, the right landing gear strut was serviced with nitrogen, and the brake system was checked with no anomalies or hydraulic leaks noted. The pilot reported that, on the day of the accident, he conducted a preflight inspection and observed no discrepancies or hydraulic leaks. He completed an engine run-up and observed no anomalies. The pilot stated that he relied on differential braking for directional control during ground operations because the airplane was not equipped with a steerable tailwheel. Although the tailwheel was equipped with a locking mechanism, the pilot reported that he typically did not engage the lock in order to maintain maneuverability on narrow runways. The pilot reported that the local flight was uneventful. During the landing roll, after the tailwheel contacted the runway, he applied the brakes and noted that the right brake pedal was ineffective. The airplane subsequently veered left, and the pilot elected to shut down the engines as the airplane departed the narrow runway and impacted a tree. The pilot reported that the right engine briefly continued operating after impact until it was shut down. A witness video of the landing roll confirmed that the airplane began to veer left shortly after the tailwheel contacted the runway. A postaccident examination of the airplane revealed a loose right brake line fitting near a section of the landing gear assembly that flexed during gear movement. Hydraulic fluid leakage was observed at the brake line fitting, and the brake line B-nut fitting was found finger-tight. Hydraulic fluid residue was also observed on and around the B-nut fitting mount. A digital video camera was recovered from the wreckage and its contents were successfully downloaded. The video files included portions of the accident flight, but not the landing or accident sequence.