I just don't see Detroit getting anywhere near as bad as New York. The population density just isn't there - half of Detroit is vacant land at this point with around half a million people. New York had nowhere to build, so instead of out, they went up.
The problem with Detroit is there are many people that are not incredibly intelligent. There is a large part of the area that is low income and just plain very reliant on the government for everything they do. So, in that vein, probably not much different than parts of NY.
The key is in how soon good, reliable information is communicated to the masses, and then whether they will listen. Just yesterday I saw a group of younger kids here in Florida getting together, not observing social distancing rules, and then going out for things like motorcycle rides. The rides might not be bad, but the meet up before the rides could be. A week ago, I rode my bike to a parking lot (my normal spot to stop for 5 minutes and turn around), for a paved bike trail, and it was packed with cars and people. There was a group of 10 - 15 high school kids, apparently all from the same track team, who were within 2 feet of each other, all waiting to go for a run on the trail. I turned around and got out of there as fast as I could. So a lack of intelligence may not be unique to Detroit, or NY, or Florida.
NYC is a whole different ballgame than even a big city like Detroit. NYC is still the epicenter of business world, and international travel to and from NYC has to greater than Detroit, so more chances for the disease to have been introduced much sooner than in other places. Only Los Angeles, and maybe to a degree Chicago come close to NYC, with regard to commerce, International travel and population density.
