I can't remember the exact names, but I seem to recall that at least a couple have closed in the past.
I wouldn't worry too much though. Since nobody's having to be paid (stagehands, actors, musicians, etc...) the producers only have to worry about covering fixed costs like insurance, so as long as this doesn't go on much more than a week or two (and a lot of people are speculating this should be over by Thanksgiving), I think every show should re-open.
"What a story........ everything but the bloodhounds snappin' at her rear end." -- Birdie
[http://margochanning.broadwayworld.com/]
"The Devil Be Hittin' Me" -- Whitney