During landing, the airplane encountered what the pilot described as a light, left crosswind. He said he corrected for the crosswind by lowering the left wing and applying opposite rudder to keep the nose straight. He said the airplane began drifting (skipping) to the right. He then applied full left rudder and the airplane ground looped to the right. The onscene investigation found the left wing main spar and skin had wrinkles in them, and the left main landing gear leg was protruding through the right wing.