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Good evening. Here’s the latest.

Credit…Mike Blake/Reuters

1. Federal health workers may have been exposed to the coronavirus without proper training or equipment and were then allowed to travel freely, a whistle-blower said.

The whistle-blower, an official at the Department of Health and Human Services, said the team was “improperly deployed” to two military bases in California last month, above, to assist the processing of Americans who had been evacuated from coronavirus hot zones. Some staff members were ordered to enter quarantined areas, and at least one stayed in a nearby hotel and left California on a commercial flight.

After a phone call with health agency leaders to raise their fears about exposure to the virus, staff members described a “whitewashing” of the situation, characterizing the response as “corrupt” and a “cover-up.”

The Centers for Disease Control and Prevention broadened the criteria for testing for coronavirus after criticism of narrow protocols that led to a delay in diagnosis of a case. A California patient who had no known risk factors tested positive for the virus. Here’s the latest.

2. A global stock market meltdown entered its sixth day as the virus has put pressure on businesses and supply chains around the world.

The S&P 500 fell 4.4 percent on Thursday, the worst single-day slide for the market since August 2011.

The speed of the market turndown has been stunning. The S&P 500 was at a record high just a week ago and has fallen more than 10 percent since, a drop known as a correction. The Dow is also at risk for a correction.

The last time stocks in the U.S. fell that much was late 2018, when investors worried that the trade war and rising interest rates might tip the U.S. economy into a recession.

3. Bernie Sanders may have a superdelegate problem.

We spoke to 93 Democratic superdelegates, party leaders who are called on to help choose a nominee if no candidate wins a majority of delegates in the primaries. Most of them said Mr. Sanders should not get the nomination outright if he falls short of that mark, even if he has a plurality.

That’s raising speculation about a brokered or contested convention. It wouldn’t be the first.

A lot is riding on Super Tuesday — including the possibility of splintered primaries and the first real test of Michael Bloomberg’s candidacy. Mr. Bloomberg has been preparing for it by blanketing the country with ads on an extraordinary scale.

4. Is this the beginning of the end of the Afghan war?

The signing of a deal between the Taliban and the U.S. is expected to go ahead on Saturday, a major step in the pathway to peace for a country scarred by more than four decades of conflict.

A weeklong, partial cease-fire was a prerequisite for the signing of the deal, and it has appeared to work, leading to as much as an 80 percent drop in major attacks, officials said. That’s likely enough for American negotiators to move ahead with the deal.

Separately, we’re following reports out of Syria where at least 22 Turkish soldiers were killed in an airstrike that could drastically change the course of the Syrian war.

5. The Indian government and the police in New Delhi are under fire for failing to quash the sectarian violence that has rocked the capital in the past week.

The riots between gangs of Hindus and Muslims have become the worst religiously motivated brutality in India in years. At least 38 people have died, as more accounts emerge of brazen religious targeting.

The government asked for more time to investigate after police officials addressed accusations that they ignored specific intelligence about armed Hindus coming together to challenge Muslim protesters. Intelligence agents in the police services requested more forces to be deployed, but the chaos only grew, according to Indian media.

6. A state-of-the-art tool used by the oil industry to avoid harming polar bears in Alaska may not be all that.

A new study suggests that a camera technique used to spot polar bear dens identifies fewer than half of them, casting doubt on the tactic’s effectiveness. The potential threat to polar bears in the Arctic refuge has become a major issue as the Trump administration pushes for more drilling in the area.

Scientists and conservationists have worried about damage by human encroachment in the relatively pristine polar area, much as they are about Antarctica, which has had a recent boom in tourism.

7. Henry VIII’s wives are coming to Broadway, reimagined as pop stars.

Embraced by a youthful fan base for its catchy (and social-media-amplified) score, the new musical “Six” conceives a concert in which the Tudor queens compete for audience approval, singing about oft-grisly marital misfortune.

And on Wednesday, Madison Square Garden opened its doors to thousands of New York City students for a performance of “To Kill a Mockingbird,” the first time a Broadway play has graced the arena. Needless to say, traditional standards of theater decorum went out the window.

8. Mets fans are taking the team’s thrifty spending habits into their own hands.

In response to the Mets’ decision not to pursue costly players and coaches this off-season, fans bombarded the team’s general manager, Brodie Van Wagenen, with small cash payments on the money-sharing app Venmo.

“So many of the issues with this team throughout my life as a fan have just stemmed from finances, and I guess this was the only tool that I had,” said one fan who sent Mr. Van Wagenen one cent.

9. A star of 1980s kitchens is making a comeback: the boneless, skinless chicken breast.

The terribly uncool cut took a back seat over lack of flavor and the tendency to dry out easily. Our Food contributor developed three fail-safe ways to leverage chicken breasts’ strengths: crisping, glazing or marinating them.

Have you heard about the Very Good Salmon, smothered in a tangy dressing made from whole lemons, diced shallot and herbs? It’s Alison Roman’s latest. Your briefing writer made it for dinner last night and can fully endorse its very goodness.

10. And finally, the leopard cub with the lion mom.

The lions and leopards of Gir National Park in India normally do not get along. But about a year ago, a young lioness in the park put the animosity aside: She adopted a baby leopard.

The lioness spent weeks nursing, feeding and caring for the two-month-old cub until he died of natural causes, treating him just like her own pair of sons, who were about the same age. Researchers say this was a rare case of cross-species adoption in the wild, and the only documented example involving animals that are normally strong competitors.

Have a lovable night.

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