The pilot was performing a touch-and-go landing. After an uneventful touchdown and rollout, and just prior to his application of power to takeoff, the airplane swerved “pretty severely to the right” despite his counter controls. The airplane then veered off the right side of the runway, into the grass and the left main landing gear collapsed under the fuselage, which resulted in substantial damage to the left wing and fuselage. Postaccident examination of the airplane by a Federal Aviation Administration Inspector found that the left main landing gear airframe cross tube had fractured, and a significant amount of corrosion and rust was visible. However, this corrosion was not visible until a section of riveted fairing was removed. Given this information, it is likely that the corroded left main landing gear cross tube failed during the landing, which resulted in a loss of directional control during the takeoff attempt, and a subsequent runway excursion.