Wall Street took another dive Friday as the Dow Jones Industrial Average sunk by 916 points and saw 18 percent of its value disappear over the course of the week.
The Dow saw all the gains made since President Donald Trump took office erased.
Also in New York City, the suspended presidential campaign of former Mayor Michael Bloomberg told staffers Friday there was a confirmed case of COVID-19 at its Times Square headquarters, a campaign official confirmed to NBC News.
New York Mayor Bill de Blasio said Friday evening the city has 5,151 coronavirus cases and 29 deaths associated with the virus. "We are now the epicenter of this crisis" in the United States, he said.
In California the number of cases, more than 1,000, has doubled in three days. Los Angeles County, the nation's most populous, reported it now has a total of 292 cases.
There are now more than 250,000 confirmed cases of the coronavirus around the world, according to Johns Hopkins University.
- Here's what to know about the coronavirus, plus a timeline of the most critical moments.
- MAPS: Where cases have been confirmed in the U.S. and worldwide.
Download the NBC News app for latest updates on the coronavirus outbreak.
This live coverage has ended. Continue reading March 21 Coronavirus news.
Army Corps of Engineers scouting NYC buildings for hospital use
The head of the U.S. Army Corps of Engineers said Friday it's scouting hotels, dorms and other buildings in New York City that could be converted into field hospitals with 10,000 beds.
Lt. Gen. Todd Semonite said the Federal Emergency Management Agency gave the Corps $1 million Tuesday to start the process and that FEMA said more money will be provided as needed.
Semonite said the corps has already looked at the huge Jacob Javits Convention Center on the western edge of Manhattan and some State University of New York buildings.
Corps engineers were also visiting other buildings to assess them Friday, he said.
New York mayor says city is 'epicenter' of U.S. crisis
New York Mayor Bill de Blasio said Friday the nation's largest city has recorded 5,151 coronavirus cases and 29 deaths.
"We are now the epicenter of this crisis," he said.
De Blasio calculated the city has about a third of the nation's cases overall, although a lag in testing in some areas could distort the numbers.
He criticized the federal government's response, saying, "Everything makes sense until you get to the federal government. Mobilize our armed forces - we need their ability."
De Blasio said he would ask police to enforce social distancing at crowded markets.
Rikers Island inmate details coronavirus fears
Inmates were puzzled when a flier about the coronavirus was handed out at the Rikers Island jail complex in New York City on Thursday. “It said stay six feet away from other people,” Juan Giron, 29, who is locked up on robbery charges, told NBC News. “But somebody sleeps three feet away from me in a dorm.”
That reality has prompted prison reform advocates and even jail doctors to call for the release of inmates amid fears of a coronavirus outbreak behind bars. Mayor Bill de Blasio announced on Thursday that he has ordered the freeing of vulnerable inmates, starting with an initial group of 40. The mayor said one Rikers Island inmate has tested positive. At least three corrections officers have also contracted the virus.
“There’s going to be a huge explosion of cases,” said Malachi Robinson, the criminal justice campaign director for the advocacy group Color of Change. “Rather than expose more people, they should start releasing them swiftly.”
Giron, who arrived at Rikers from an upstate prison on Tuesday and is awaiting a court hearing after his sentence was vacated, said the facility is crowded and filthy. His first day, he said, was spent in a packed intake room with other inmates awaiting medical testing and a transfer to a housing area. “It’s disgusting in here,” said Giron. “And people are coming in and out of Rikers from the streets. Who knows who has this stuff?”
FDA is working on treatment with blood from recovered patients
Dr. Arturo Casadevall was working from home in Baltimore on Thursday when his phone started to buzz with messages from colleagues.
The commissioner of the Food and Drug Administration had just announced during a White House press briefing that the agency was investigating the possibility of using blood plasma donated by recovered coronavirus patients as a promising short-term treatment for the virus.
For weeks, Casadevall has led an ad hoc team of researchers from across the country who are working to establish a network of hospitals and blood banks that can begin collecting blood serum or plasma from coronavirus survivors, with the hopes of using it to treat critically ill patients and boost the immune systems of hospital workers.
Confirmed coronavirus case at Bloomberg campaign HQ
The Bloomberg campaign notified staffers today of a “confirmed case of COVID-19” in the campaign’s Times Square headquarters, a campaign official confirms to NBC News.
Staffers were notified by human resources that the case impacted two floors of the building and that the individual was last in the office on Monday.
It’s unclear whether the person who tested positive for coronavirus worked for the campaign or was a contractor with access to the building. The campaign declined to say.
This news comes the same day that the Bloomberg campaign announced it is laying off its staff, who will lose their health insurance at the end of April. Bloomberg ended his three-month presidential bid earlier this month.
National sports groups call for postponement of Olympics
USA Swimming published an open letter Friday calling for the postponement of the Tokyo 2020 Olympics and Paralympics until next year.
"Our world class swimmers are always willing to race anyone, anytime and anywhere; however, pressing forward amidst the global health crisis this summer is not the answer," it said in the letter.
Other national athletic bodies have also started raising concerns about holding the Olympics as scheduled from July 24 to August 9 and the Paralympics from August 25 to September 6. They include the British Olympic Association, the British Paralympic Association, the Norwegian Sports Federation and the Olympic and Paralympic Committee.
Photo: Drive-thru confession
America's only community centers: Your local supermarket
With most U.S. businesses shuttered in the fight to contain coronavirus, grocery stores have become the unlikely center of American society.
Recent days have been "unlike anything I’ve ever seen at work," as "stockers were getting pushed out of the way for toilet paper" and customers were "fighting over beans," said Journey Carnahan, who works at H-E-B Grocery in central Texas.
Read the full story here.
Illinois issues stay-at-home order for residents
The governor of Illinois on Friday issued a stay-at-home order, making it the latest state to make such a sweeping mandate in the fight against the spread of the new coronavirus.
California issued a stay-at-home order Thursday, and New York's governor mandated that all nonessential businesses keep workers at home. Pennsylvania's governor has also ordered that all businesses that are not "life-sustaining" close.
Illinois Gov. J.B. Pritzker said he did not "come to this decision easily" but believes it is necessary to slow the spread of the coronavirus. The order is expected to become effective Saturday.
States push price-gouging measures as coronavirus fuels consumer fears
As states across the country shutter restaurants, bars and schools for the next several weeks or more to slow the spread of the coronavirus, some are looking to pass legislation to stop businesses that remain open from price-gouging fearful U.S. consumers.
Price gouging — the practice of charging exorbitant prices for essential items in times of high-demand — is prohibited during times of crisis in about two-thirds of the United States. As public panic surrounding COVID-19 heightens, consumers have been flocking to stores to stock up on supplies like face masks, hand sanitizer and disinfectant wipes — to the exploitation of some retailers.
While online marketplaces like Amazon and Walmart have taken steps to prevent the practice by suspending offers from sellers charging unfair prices, brick-and-mortar stores are being closely monitored by state governments, several of which are considering legislative action.
Read the full story here.