Just got this notice from building management:
We are sending out this letter to make you aware of a potential case of Norovirus reported by a tenant in the building. Norovirus is contagious and symptoms usually show up 12 to 48 hours after exposure, however an infected person can remain contagious for up to 3 days after symptoms have subsided. The office spaces occupied by those that have been sick and all common areas have been disinfected and we will continue to disinfect on a nightly basis over the course of the next week.
My building has the 12 on it. They should have cited to http://www.about-norwalk.com/
And, I might say, building management has done a great job dealing with this.