Friend in NYC was telling me just how few people that live in the apartments have their own laundry machines. Just a guess but I bet that is one source of infections, because people have to wash things still - and in those communal laundry rooms you probably can’t expect to be alone. Her cousin was a doorman in a higher end building and he passed away in early April from it, probably got it from a resident.
Makes sense. Even going downstairs to get the mail would mean going through a high traffic area.