Put diced tomatoes, vegetables and Italian seasoning in a saucepan. Cook until vegetables are softened. Use food chopper or blender to chop vegetables into smaller pieces. Add meat and water to tomato sauce mixture.
In separate bowl, mix ricotta cheese, 1-1/2 cups mozzarella, 2 T Parmesan, egg & parsley.
Spoon 1 cup meat sauce into slow cooker; top with 3 noodles, broken to fit; put cheese mixture on top of noodles, then cover with more meat sauce. Continue with noodle-cheese-sauce layers until all mixtures have been used.
Put lid on slow cooker and cook on low for about 6 hours (noodles should be soft when fork is inserted). Sprinkle with remaining cheeses; let stand, covered, 10 minutes or until melted.