AP Week in Pictures, North America

President Donald Trump speaks during a press briefing with the coronavirus task force, at the White House, Wednesday, March 18, 2020, in Washington. (AP Photo/Evan Vucci)

Reporters raise their hands to ask President Donald Trump questions during a press briefing with the coronavirus task force, at the White House, Monday, March 16, 2020, in Washington. (AP Photo/Evan Vucci)

A woman walks through a lightly trafficked Times Square in New York, Monday, March 16, 2020. Bars and restaurants will become takeout-only and businesses from movie theaters and casinos to gyms and beyond will be shuttered Monday night throughout New York, New Jersey and Connecticut because of the coronavirus, the states' governors said. (AP Photo/Seth Wenig)

Neal Browning receives a shot in the first-stage study of a potential vaccine for COVID-19, the disease caused by the new coronavirus, Monday, March 16, 2020, at the Kaiser Permanente Washington Health Research Institute in Seattle. Browning is the second patient to receive the shot in the study. (AP Photo/Ted S. Warren)

A person is taken on a stretcher into the United Memorial Medical Center after going through testing for COVID-19 Thursday, March 19, 2020, in Houston. People were lined up in their cars in a line that stretched over two miles to be tested in the drive-thru testing for coronavirus. (AP Photo/David J. Phillip)

A trader holds his hand to his head after trading was halted at the New York Stock Exchange, Wednesday, March 18, 2020, in New York. (AP Photo/Mark Lennihan)

People wait for an H-E-B grocery store to open Tuesday, March 17, 2020, in Spring, Texas. Grocery store executives and city officials reassured the community, on Monday, that plenty of food will be available in their stores and urged people not to stockpile groceries amid coronavirus concerns. (AP Photo/David J. Phillip)

A medical worker tests a person for the coronavirus at a drive-through facility primarily for first responders and medical personnel in San Antonio, Tuesday, March 17, 2020. Texas Gov. Greg Abbott said, "This is not a time to panic. It's not as if we have never been through this before. We've been through this many, many times." (AP Photo/Eric Gay)

Former Vice President Joe Biden, left, and Sen. Bernie Sanders, I-Vt., right, greet one another before they participate in a Democratic presidential primary debate at CNN Studios in Washington, Sunday, March 15, 2020. (AP Photo/Evan Vucci)

Cece Guida, 19, top, of New York City, pushes on Sam Reddick, 20, of Evansville, Ind., as spring break revelers look on during a game of chicken fight on the beach, Tuesday, March 17, 2020, in Pompano Beach, Fla. As a response to the coronavirus pandemic, Florida Gov. Ron DeSantis ordered all bars be shut down for 30 days beginning at 5 p.m. and many Florida beaches are turning away spring break crowds urging them to engage in social distancing. (AP Photo/Julio Cortez)

Micha Robbins, 4, tries to touch the nose cone of a F/A-18 Hornet Blue Angel as the Navy's Demonstration team landed Wednesday, March 18, 2020, in Waco, Texas to refuel. (Jerry Larson/Waco Tribune-Herald via AP)

Aliyah Mosby is silhouetted against the sunset as she walks at the Liberty Memorial Thursday, March 19, 2020, in Kansas City, Mo. Mosby was taking advantage of warm weather on the first day of spring to get some fresh air as most of the community isolates to limit the spread of the coronavirus. (AP Photo/Charlie Riedel)