What is the criteria for tearing down buildings? Is there some formula the city is using to determine which buildings meet the wrecking ball first?

I know it's Detroit, yata, yata... but it seems like the buildings that are being torn down first are the ones with the most potential of being restored. They are also often the most historical. The city has thousands of abandoned structures. Why is it that the ones who meet the reaper first are the buildingas that everyone seems to cherish?

I mean there are numerous examples, but the Lafayette Building, Cass Tech, now maybe Carl's Chop House. What's the deal? Bulldoze the the insignificant buildings first, at least you give the more important structures a chance of being rehabbed. What's the harm in that? Seems totally senseless to start with iconic structures. If nothing else, it is demoralizing.