Confirmed coronavirus cases in New York City are just “the tip of the iceberg,” New York City Health Commissioner Dr. Oxiris Barbot said Thursday, adding that “close to a million” residents have probably been exposed to Covid-19. More than 147,000 people in New York City have so far tested positive for Covid-19, according to data compiled by Johns Hopkins University. “That really I think is the tip of iceberg for a number of different reasons,” Barbot said at a news briefing. “New Yorkers have been heeding our advice that if they have mild symptoms, at this point in time, when...