WASHINGTON — Multiple members of the U.S. Secret Service have tested positive for COVID-19, the disease caused by the coronavirus, according to Department of Homeland Security documents reviewed by Yahoo News. In March, the Secret Service, which is responsible for the protection of President Trump and other leaders, acknowledged that a single employee tested positive in March. However the problem is currently far more widespread, with 11 active cases at the agency as of Thursday evening, according to a daily report compiled by the DHS. This report comes as a pair of cases among White House staffers close to Trump...