March 11, 2020: The Day Everything Changed

A year into the coronavirus pandemic, the enormous changes in our lives have become unremarkable: The collection of fabric masks. Visits with friends or family only in small outdoor gatherings. Working or learning from home. Downtowns deserted at noon on a weekday.

While some changes happened gradually, there was one day that marked the beginning of the new normal, though that wasn't clear as the day began.

March 11, 2020. On that day in the United States, the pandemic future arrived all at once.

March 11 was a Wednesday. Joe...