I would imagine ND has more firearms than Chicago with a smaller total population. FBI[1] has listed 9 murders in 2009 and 3 were firearm related. Of the 3 in 2008[2], 0 were firearm related. Gun control doesn't stop people from killing others, it just makes them use something else. The something else can be a lot worse.
I am not in the mood for a debate on gun control. I do agree that guns aren't a prerequisite for violet death but they do make the process significantly easier given they are designed for that purpose.
The important question is "why?" not "how?" - concentrating on any tool is missing the real problems and solutions in life.
The tools isn't Chicago's problem or else it would cause the same problem in ND. My cousin is alive because he had a shotgun on him when attacked by abandoned dogs. I don't blame the dogs ("how"). I blame the owner's who abandoned them ("why").
Your example compares apples with oranges.