A teenager’s website tracking coronavirus has become one of the most vital resources for people seeking accurate and updated numbers on the pandemic. The URL is nCoV2019.live. We speak with 17-year-old Avi Schiffmann, a high school junior from Mercer Island outside Seattle, who started the site in late December, when coronavirus had not yet been detected outside of China. Now the site has been visited by tens of millions, from every country on Earth. It tracks deaths, numbers of cases locally and globally, and provides an interactive map, information on the disease, and a Twitter feed. The resource updates every minute or so, and pulls information from the World Health Organization, the Centers for Disease Control and elsewhere.