Just to go over one point so as to not give the wrong impression. Fuel is carried in the wing structure of Cessnas, Pipers, Mooneys, Rockwells and Cirri. That is fuel is immediately behind the single skin thickness leading edge of the wing - the same bit that will get bent as a Cirrus wing. I'm not an expert on design but materials and perhaps composite structure does crack more easily than ali but ali splits quite often as well in an accident.