Cook sausage slowly in heavy skillet until brown, crumbly and done. Add tomatoes and corn, simmer for 10 minutes. Saute onion in bacon drippings; mix flour, sugar and salt; blend with bacon drippings and onion. Add to sausage and vegetables; heat to boiling point. Spoon into 2 quart baking dish; top with bread crumbs. Bake at 425°F for 20 minutes, or until topping is browned.