The head of the World Health Organization warned that politicizing the pandemic would result in “many more body bags.”

New York State alone now has more confirmed coronavirus cases than Italy.

Don’t count on the coronavirus fading in hot weather the way some other viruses do, the National Academy of Sciences said.

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Why N.Y. has so many cases: ‘Everything was slow’

The coronavirus struck the U.S. first on the West Coast, but hardest in New York, where at least 6,268 people have died since the state’s first positive test on March 1. “The bad news isn’t just bad,” Gov. Andrew M. Cuomo said Wednesday. “The bad news is actually terrible.”

It’s likely that nothing could have completely prevented America’s biggest and densest metropolis from being walloped. But early on, when swift action might have made a big difference, the official response was hampered by confused guidance, unheeded warnings, delayed decisions and political infighting, a team of Times reporters found.

The virus “was spreading widely in New York City before anyone knew it,” said Dr. Thomas R. Frieden, a former head of both the Centers for Disease Control and Prevention and the New York City Health Department.

Dr. Frieden said that if the state and city had acted a week or two earlier to order social distancing, close businesses and tell people to stay home, the outbreak might have claimed half as many lives, or even fewer. But New York was days behind California and Washington State in taking those measures.