We made it a few answers without anyone refuting the fallacy that Covid is coastal.
I mean, I guess Detroit and Chicago are coastal. But more importantly, they're major hubs for international travel, and a huge portion of their population uses public transit.
I spend a lot of time in NYC. I ride the E and F trains a lot (and the Q70, Q46, sometimes the Q54 and Q60 for those keeping track). I have no idea how I'd stay six feet apart from everybody.
On the left coast, I use the LA Metro more than the typical Angeleno. It's sad to say, but it probably cut down the spread significantly. (On the bright side, they now have clean air for the first time in 70 years.)
The bay area has terrible, if ubiquitous, transit. And whether people were already hunkered down, I still want to give BART the finger.