The Latest: South Korea reports 20 new virus cases, China 4

The Latest on the coronavirus pandemic. The new coronavirus causes mild or moderate symptoms for most people. For some, especially older adults and people with existing health problems, it can cause more severe illness or death.
TOP OF THE HOUR:
— South Korea reports 20 new coronavirus cases, China announces 4.
— Denver mail distribution center closed after employees test positive.
— Trump to order U.S. flag flown at half-staff over next 3 days as COVID-19 deaths approach 100,0