Chalk's Ocean Airways Flight 101 crash (a Grumman Mallard G-73T) was not caused specifically by corrosion, but by a crack in a stringer in the wing that was never repaired properly. The crack propagated to total wing separation in flight.
However, after the remainder of Chalk's Grumman Mallard aircraft were grounded, unacceptable corrosion was found in a number of their grounded aircraft. Sub-standard repairs on the aircraft were also noted.
Chalk's Ocean Airways Flight 101 crash - Dec 19, 2005