Dr. Angela Chen diagnosed the first case of COVID-19 in New York City. The emergency room physician says she’ll never forget the fateful day. Patient zero, a 39-year-old health care worker, recovered from the virus. But in March 2020, no one could have imagined how drastically everyone’s lives would change. Chen was worried about bringing the virus home to her husband and baby boy, and sent them to stay with family. For months she saw him only through windows and missed several big milestones.