New York was still making money a week ago. A few people wearing masks, some closings, but generally business as usual. And then we tumbled down a cliff. By Friday, commuters arriving at Grand Central Terminal paused as they entered the main concourse — stunned by its emptiness, the usual din quieted by stay-at-home orders from companies and the government. For the first time, the vast, star-covered ceiling seemed appropriate.

Earlier this month, I started to travel the city to document the onset of one type of economic activity — the anxious purchase of emergency supplies — and the collapse of many, many others.