On September 12, 2019, at 0225 Atlantic standard time, a Piper PA23-250, N269KW, was substantially damaged while taxiing at Cyril E King Airport (TIST), Charlotte Amalie, U.S. Virgin Islands. The commercial pilot was not injured. The airplane was registered to Executive Airshares, LLC, and operated under the provisions of Title 14 Code of Federal Regulations Part 91. Night, visual meteorological conditions prevailed, and the personal flight was destined for Henry E Rohlsen Airport (TISX), St. Croix, U.S. Virgin Islands. According to the pilot's written statement, he "added throttle to get the temp[eratures]s up" back taxiing to Runway 10. He cycled the propeller twice, pulled the throttle back to idle, heard an irregular noise and then felt ground contact. He immediately shut off the mixtures to both engines. The pilot reported that "the gear was slowly collapsing" while he was taxiing, "which could not be recognized in the dark." Inspection of the accident site and wreckage by a Federal Aviation Administration (FAA) inspector revealed a 60 to 70 ft ground scar on the runway leading to the runway edge, consistent with the left landing gear and wingtip. Ground scars were observed in the turf from the runway edge leading to where the airplane came to rest after striking a runway light. The left-wing leading edge was fractured and impact damaged in several areas and the wing spar was substantially damaged. The trailing edge of the outboard left wing displayed damage consistent with ground and runway contact. The landing gear was examined under the supervision of the FAA inspector. The inspector noted no evidence of landing gear structural damage and no malfunction of the landing gear actuator. A retraction test revealed no mechanical failures and a hydraulic pressure test revealed no anomalies. According to maintenance records, the airplane's most recent annual inspection was completed on July 1, 2019, at which time a landing gear retraction test was performed with no anomalies noted.