Democratic U.S. presidential candidate Senator Elizabeth Warren greets people during a campaign stop in Las Vegas, Nevada, U.S., February 15, 2020.

Daytona Beach, Florida, USA; NASCAR Truck Series driver Ty Majeski (45) slides on his roof after flipping over in a crash during the NextEra Energy 250 at Daytona International Speedway. Mandatory Credit: Mark J. Rebilas-USA TODAY Sports

Democratic U.S. presidential candidate Senator Bernie Sanders speaks during a campaign rally in Las Vegas, Nevada, U.S., February 15, 2020.

Nepalese nationals who were in the coronavirus-stricken Chinese city of Wuhan walk out from a Nepal Airlines Airbus A330-200 plane carrying 175 Nepalese nationals, before they were sent to be quarantine, at Tribhuvan International Airport in Kathmandu, Nepal February 16, 2020.

Soccer Football - Premier League - Aston Villa v Tottenham Hotspur - Villa Park, Birmingham, Britain - February 16, 2020 Aston Villa's Pepe Reina, Bjorn Engels and teammates look dejected after conceding their third goal REUTERS/Phil Noble

Workers wearing protective suits and face masks disinfect a residential compound, following an outbreak of the novel coronavirus in the country, in Taiyuan, Shanxi province, China February 15, 2020. Picture taken February 15, 2020. cnsphoto via REUTERS.

Luge - 2020 FIL World Luge Championships - Men's Singles - Sliding Center Sanki, Sochi, Russia - February 16, 2020 Korea's Lim Namkyu in action during his run as spectator takes a selfie.

A family look at pigeons as they pass time at a temple in Kathmandu, Nepal February 16, 2020.

Daytona Beach, Florida, USA; NASCAR Truck Series driver Tate Fogleman (02) catches fire after a wreck in turn three with NASCAR Truck Series driver Angela Ruch (00) during the NextEra Energy 250 at Daytona International Speedway. Mandatory Credit: John David Mercer-USA TODAY SportsFeb 14, 2020; Daytona Beach, Florida, USA; \m during practice for the Daytona 500 at Daytona International Speedway. Mandatory Credit: John David Mercer-USA TODAY Sports.

People react inside a car converted to sauna during the European Sauna Marathon in Otepaa, Estonia February 15, 2020.

Democratic 2020 U.S. presidential candidate and former U.S. vice president Joe Biden attends a campaign event in North Las Vegas, Nevada, U.S., February 15, 2020.

Dogs wearing masks are seen at a main shopping area, in downtown Shanghai, China, as the country is hit by an outbreak of a new coronavirus, February 16, 2020.

A bride sits in a limousine at a wedding chapel on Valentine's Day in Las Vegas, Nevada, U.S., February 14, 2020.

A surfer rides a large wave at Praia do Norte in Nazare, Portugal February 15, 2020.

Biathlon - 2020 Biathlon World Championships - Men's 10 km Sprint Competition - Antholz-Anterselva, Italy - February 15, 2020 Latvia's Aleksandrs Patrijuks, Bulgaria's Anton Sinapov and Sweden's Jesper Nelin react after the race.

An Afghan man cries over the body of one of the victims of Friday's air strike in Surkhroad district of Nangarhar province, Afghanistan February 15, 2020.

A couple wearing masks kiss at a main shopping area, in downtown Shanghai, China, as the country is hit by an outbreak of a new coronavirus, February 16, 2020.

Cricket - South Africa v England - Third T20 - Supersport Park, Centurion, South Africa - February 16, 2020 England's Ben Stokes attempts to run out South Africa's David Miller.