On April 17, 2026, about 1750 eastern daylight time, a Mooney M20J, N1151H, was destroyed when it was involved in an accident near Union, South Carolina. The pilot and 3 passengers were fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. A review of preliminary ADS-B data revealed that during cruise flight about 1 hour and 13 minutes into the cross-country flight, the airplane diverted south and landed on runway 5 at Union County Airport (35A), Troy Shelton Field, Union, South Carolina. Surveillance video from the airport security system showed the accident airplane taxi to the airport fuel pumps after landing. The occupants disembarked and the pilot refueled the airplane. About 30 minutes after landing, the occupants boarded the airplane and then taxied to the departure end of runway 23. A few minutes later another video captured the airplane during climbout about 1,000 ft from the departure end of runway 23, about 200 ft above ground level. The airplane banked right then quickly rolled left and descended behind trees. Subsequently, a plume of smoke rose from the trees. No one was reported to have witnessed the accident flight. The accident site was located in wooded and hilly terrain about 1,270 ft from the departure end of runway 23. The accident site was at an elevation of about 520 ft mean sea level (msl) and on a magnetic heading of about 223° from the departure end of runway 23. The debris field was on slightly sloping terrain and all of the wreckage remained within a radius of about 40 ft from the main wreckage. The majority of the wreckage was consumed by postimpact fire. All primary flight controls were observed during the accident site examination. Small portions of the vertical stabilizer and rudder were observed attached to the empennage, which exhibited excessive thermal damage and remained attached to the main wreckage. The wreckage was relocated to a secure facility for further examination.