On July 1, 2004., at 2030 central daylight time, a Cessna 310P, N310WH, piloted by a commercial pilot, received substantial damage on impact with terrain when the right main landing gear collapsed during touchdown on runway 36 (4,400 feet by 50 feet, asphalt) at Starke County Airport (OX1), Knox, Indiana. Visual meteorological conditions prevailed at the time of the accident. The 14 CFR Part 91 personal flight was operating on an instrument rules flight plan. The commercial pilot was uninjured. The flight originated from Evansville Regional Airport, Evansville, Indiana, at 1900, and was en route to OX1. The pilot stated that he was five miles from OX1 when he extended the landing gear, and the right main landing gear position indicator light did not illuminate. He then recycled the landing gear and obtained three green landing gear position indicator lights. He also heard the down locks snap into place. Upon touch down, the landing gear warning horn annunciated and he right main landing gear position indicator light extinguished. The landing gear collapsed and the airplane then impacted a birm on the right side of the runway. The 1969 Cessna 310P, serial number 310P0204, airplane was registered to the pilot. The airplane was last inspected during annual inspection on December 14, 2003, at a total time in service of 5,739 hours. The pilot stated that the airplane accumulated an additional 48 hours of time after the of the annual inspection. The number of cycles was unknown. Examination of the right landing gear revealed that the brace assembly - right hand side, part number 5041000-46, was fractured. The fracture surface displayed multiple initiations at the edge of the slot and an oxidized area with a distinct terminus, features consistent with fatigue.