Don't think your yard is free of predators just because you live in the city. Raccoons come up through storm drains and arrive in very urban areas. These agile animals can climb tress and open doors. Wire cages are no protection for your bunny. If your bunny cannot stay in your house at night, make sure that he's enclosed within solid walls and behind a solid door a garage, shed, or basement with a good lock.
Some outdoor rabbits avoid death by predator or the other risks mentioned.
A life spent confined to a hutch is boring, depressing, and stressful for a sensitive creature such as a rabbit. A life spent unconfined but outdoors is simply too dangerous for domestic animals. By domesticating them, we have deprived them of whatever natural ability they had for survival on their own. If your rabbit currently lives outdoors, we strongly urge you to bring her in at least during the night, when predators are most common. Even if she's confined to a smaller cage, or a bathroom or utility room, she's safe, and she's making a first step to being part of your family.