When Michelle Alfaro left her office at the United Nations in Geneva on March 13, her job finding homes for the world's most vulnerable refugees was under control.

Four days later, the new coronavirus had knocked it into chaos. Governments across the world announced border closures, lockdowns and flight cancellations. The United Nations was forced to suspend the program.

"Everything collapsed that week," said Alfaro, who manages resettlements for the U.N. refugee agency, UNHCR.