Expressways are seen with less traffic near the Pearson International Airport in Toronto, Canada, March 21, 2020. At midnight on Friday the land border between Canada and the United States was closed to all non-essential travel in an effort to stem the spread of COVID-19. (Photos: Zou Zheng/Xinhua)

The security gates to the U.S. are seen with few people at the Terminal 3 of the Pearson International Airport in Toronto, Canada, March 21, 2020. At midnight on Friday the land border between Canada and the United States was closed to all non-essential travel in an effort to stem the spread of COVID-19.

The U.S. check-in express service area is seen with few people at the Terminal 3 of the Pearson International Airport in Toronto, Canada, March 21, 2020. At midnight on Friday the land border between Canada and the United States was closed to all non-essential travel in an effort to stem the spread of COVID-19.