Cook bacon in Dutch oven over medium heat until crisp. Remove bacon from Dutch oven, reserving drippings; drain bacon on paper towels. Set aside.
To bacon drippings in Dutch oven, add celery and onion. Cook over medium-high heat for 3 to 4 minutes or until tender, stirring frequently. Drain.
Add potatoes, broth, water, caraway seed and cooked bacon. Bring to a boil. Reduce heat; cover and simmer 6 to 8 minutes or until potatoes are tender, stirring occasionally.
Meanwhile, place bread slices on ungreased cookie sheet. Broil 3 to 5 inches from heat for 2 to 4 minutes or until toasted, turning once. Sprinkle each slice with about 1/4 cup cheese. Broil an additional 1 to 3 minutes or until cheese is bubbly.
To serve, ladle soup into individual soup bowls. Top each with 1 cheese-topped bread slice.