A woman wearing a protective mask walks outside Castel Sant'Angelo, as Italy tightens measures to try and contain the spread of coronavirus disease (COVID-19), in Rome, Italy March 23, 2020.

A man sits alone on a roof terrace during Italy's nationwide lockdown in Rome, Italy March 15, 2020. In the distance, no cars are seen on a usually busy highway.

A woman walks alone on Mariacka street in the usually crowded Main Town in Gdansk, during the spread of the coronavirus disease (COVID-19) in Poland, March 22, 2020.

General view of a quiet circle line tube on the London underground as the spread of the coronavirus disease (COVID-19) continues, London, Britain, March 19, 2020.

A man wearing a face mask stands in an empty park as the spread of the coronavirus disease (COVID-19) continues in Prague, Czech Republic, March 23, 2020.

A man sits alone looking towards the Washington Monument amid a dramatic downturn in tourists due to the coronavirus pandemic in Washington, U.S., March 16, 2020.

A man walks across an empty medieval Charles Bridge in Prague, following the outbreak of coronavirus disease (COVID-19), Czech Republic, March 20, 2020.

A woman walks her dog during a curfew imposed to prevent the spread of coronavirus disease (COVID-19) in Belgrade, Serbia, March 23, 2020.

A man sits alone outside a pub on Carnaby Street, as the number of coronavirus (COVID-19) cases grow around the world, in London, Britain, March 17, 2020.

A railway employee talks on the phone inside an empty train compartment after railway services were shutdown by the authorities to limit the spread of the coronavirus disease (COVID-19) in Mumbai, India, March 23, 2020.

PhD student Sergio Antonio Perea Restrepo studies alone at University of Sao Paulo (USP) campus after classes were suspended due to coronavirus disease (COVID-19) outbreak in Sao Paulo, Brazil, March 17, 2020.

A man plays alone at the game center which is almost empty amid fears of coronavirus outbreak in Bangkok, Thailand March 19, 2020.

A faithful sits alone at the empty Notre-Dame des Victoires Cathedral during the Sunday mass, as prayers were suspended over concerns of the spread of coronavirus disease (COVID-19), in Dakar, Senegal March 22, 2020.

A woman walks through empty streets outside the Public Market, amid the coronavirus disease (COVID-19) outbreak, in Seattle, Washington, U.S., March 20, 2020.

Nathan Phillips Square on the day that the province of Ontario declared a state of emergency as the number of novel coronavirus cases continued to grow in Toronto, Ontario, Canada March 17, 2020.

A general view of Copacabana beach during the coronavirus disease (COVID-19) outbreak in Rio de Janeiro, Brazil, March 22, 2020.

A person stands on the roof of a building after Cyprus registered its first death from the coronavirus disease (COVID-19) in Nicosia, Cyprus March 22, 2020.

The shadow of a conductor Mate Hamori is seen as he conducts the Danubia Orchestra without an audience in the Liszt Ferenc Academy of Music as the Hungarian government bans events hosting more than 100 people to contain the spread of the coronavirus disease (COVID-19) in Budapest, Hungary, March 13, 2020.

A woman sits alone in Thames Barrier Park in Silvertown as the spread of the coronavirus disease (COVID-19) continues, in London, Britain, March 23, 2020.

A man walks along the National Mall as museums and many public areas are closed to the public for precaution due to coronavirus (COVID-19) spread, in Washington, U.S., March 15, 2020.