Live Coronavirus News: Updates and Video

Case numbers had been lower earlier in the week, but that may have been because fewer test results were being reported each day. Nearly 69,000 results were reported on Thursday, compared with about 45,000 on Wednesday.

Vice President Mike Pence visited the state Thursday and met with Gov. Ron DeSantis to discuss the state’s rapidly worsening outbreak. The visit was quite different in tone from one in May, when the two men ate, unmasked, at a burger bar and Mr. Pence praised the state’s reopening plans, saying, “I really think Florida has set the pace.” Back then Mr. DeSantis proclaimed “we’ve succeeded,” and added, “I think that people just don’t want to recognize it because it challenges their narrative.”

On Thursday, both men wore masks, but removed them to speak at a news conference, and Mr. Pence said that the federal government would work with the state to help flatten its curve. “The economic comeback that is underway is a demonstration that we don’t have to choose between opening up America and the health of our people: We can do both,” he said. “And that’s the challenge that we face today across the Sun Belt.”

Contact tracers, unable to keep up with so many new cases, have become overwhelmed by the surge.

“We are starting to lose the ability to do contact tracing,” said Dr. J. Glenn Morris, director of the Emerging Pathogens Institute at the University of Florida.

City and county officials desperate to stop the spread have adopted local mask mandates and closed the beaches over the holiday weekend. Some communities are deploying teams of public employees to go door-to-door in the hardest hit neighborhoods, distributing masks, hand sanitizers and fliers with information on symptoms and testing.

Testing demand has remained high: In Miami-Dade County, which has averaged more than 1,400 daily cases, the biggest testing sites begin taking appointments at 9 a.m. for the next day and have filled them by 9:30 a.m., county officials said. “The requests for testing have exploded,” said Maurice Kemp, county deputy mayor.

Elsewhere in the United States:

• When South Carolina’s coronavirus case counts started to rise sharply in June, the Citadel, one of the few state-supported military colleges in the country, rolled out an elaborate plan for the football team to work out safely over the summer. But 13 players tested positive anyway, cutting the team’s training short. They were exposed by attending an off-campus party, or by living with someone who had, according to Col. Colonel John Dorrian, the college’s vice president for communications and marketing.

• N.F.L. team owners and the players’ union, mindful of other professional leagues’ struggles to return to play, are considering playing the 2020 regular season with few or no fans in attendance. They are also discussing how to absorb lost revenue potentially worth billions, according to three people briefed on the discussions who spoke on the condition of anonymity because they were not allowed to discuss the matter publicly.

• Five of the nine Atlantic City casinos were reopening Thursday but with new rules: Gamblers must wear masks, and won’t be allowed to smoke, drink or eat inside.

• In New York City, Mayor Bill de Blasio announced on Thursday that the vast majority of families have indicated that they want to send their children back to school in September, according to a survey of roughly 450,000 families. The city is still working on plans to safely maximize the number of students in schools, he said, adding that schools could shift to a staggered schedule. The governor has said logistics are up to individual districts.

• Also in New York City, 22 streets, some already closed to car traffic, will be dedicated to outdoor dining on Friday nights and weekends. The move will be key in “some places in the city where we have extraordinary restaurants concentrated in one place,” the mayor said.

• Officials rushing to contain a virus cluster tied to a party in a New York City suburb used an unusual legal strategy: issuing subpoenas to partygoers.

• Herman Cain, a former Republican presidential candidate, announced Thursday that he had been hospitalized with the virus. Mr. Cain, who attended Mr. Trump’s indoor rally in Tulsa, Okla., on June 20, learned Monday that he had tested positive, was hospitalized Wednesday and on Thursday “was resting comfortably in an Atlanta-area hospital,” according to a statement posted on his Twitter account.