On February 8, 1996, about 1720 central standard time, a Cessna 310L, N2201F, registered to Air Carriers Inc., experienced collapse of the left main landing gear during landing roll at the Auburn Opelika Airport, Auburn, Alabama, while on a 14 CFR Part 135 air taxi flight. Visual meteorological conditions prevailed at the time and an instrument flight rules flight plan was filed. The commercial-rated pilot was not injured and the airplane was substantially damaged. The flight had originated from Jacksonville, Florida, the same day about 1545. The pilot stated that during landing on runway 18, the aircraft was rolling on all three landing gear and had slowed to 40 knots when the left main landing gear collapsed. The left wing tip tank struck the runway and the aircraft rotated around 160 degrees from runway heading, where it came to rest. Postcrash examination of the aircraft was performed by FAA inspectors and company maintenance personnel. The left main gear side brace lock end fitting had failed, allowing the gear to collapse. Metallurgical examination of the failed end fitting was performed by the NTSB Material Laboratory, Washington, D.C. The end fitting failed due to overstress. See attached NTSB Metallurgist's Factual Report.