Mayor debunks the idea of returning to normal in April.

Mr. de Blasio continued to emphasize on Wednesday how urgently the city needed supplies to cope with the crush of new cases. He said he appreciated the assistance the federal government had committed to providing, but that more was required. And he again called for the U.S. military to get more directly involved and in a much bigger way.

The mayor warned New Yorkers to relinquish any hope of a return to normal life by April, rejecting the president’s comments this week that he wanted the economy to reopen by Easter. City residents should prepare for the possibility that conditions could worsen in May, he said.

Citing various projections, the mayor said at least half of all New Yorkers could contract the virus, an estimate similar to those that officials have given in California. But Mr. de Blasio noted that for 80 percent of those who were infected, it would be “a very limited experience.”

The mayor also said that New Yorkers were “overwhelmingly” following social-distancing guidelines, but that there were exceptions. To address one of those, he said, the city would remove hoops from 80 of the city’s 1,700 basketball courts where pickup games were still being played.

The first virus-related death of a homeless New Yorker is confirmed.

A man who had been living in New York City’s shelter died after being hospitalized with the coronavirus for several days, officials said on Wednesday.

It was the first virus-related death of a homeless person in the vast system of 450 traditional shelters, hotels and private apartment buildings that the city uses to house homeless families and single adults. As of Wednesday, there were 39 confirmed coronavirus cases among 27 shelters, according to the city’s Department of Social Services.

The agency did not identify the man or provide additional details about him, but said he had been living in a shelter for single adults.