Preheat ove to 450°
Place the bread in a small bowl. Sprinkle the oil and half the garlic over the bread and toss to combine. Place the bread cube on a nonstick jelly-roll pan or baking sheet and bake for 6-8 minutes, or until the croutons are golden. Shake the pan occasionally so the bread will cook evenly.
In a food processor, process the tomatoes until they are uniformly chopped. Transfer the tomatoes to a serving bowl.
Peel the onions and cut into eights. Stem and seed the bell pepper, ten cut into large piece. Peel the cucumber and cut into 1-inch pieces. Add the onion pieces to the processor and pulse on and off briefly to roughly chop. Add the onion to the tomatoes. Process the bell pepper in the same fashion and add to the tomatoes. Process the cucumber, taking care not to puree it; add it to the tomato mixture.
Stir the ice water, vinegar, sugar, and remaining garlic into the soup. Serve at room temperature or chilled, topped with the croutons.