The NCAA announced Thursday that it will cancel its annual men's and women's Division I basketball tournaments, set to begin with Selection Sunday on March 15, due to the coronavirus outbreak.

Why it matters: March Madness is a cultural phenomenon and one of the biggest sporting events in America. The NCAA was initially planning to play games without fans, but faced pressure to cancel after top-ranked teams Duke and University of Kansas suspended all athletic activities.

What they're saying:

"Today, NCAA President Mark Emmert and the Board of Governors canceled the Division I men’s and women’s 2020 basketball tournaments, as well as all remaining winter and spring NCAA championships. This decision is based on the evolving COVID-19 public health threat, our ability to ensure the events do not contribute to spread of the pandemic, and the impracticality of hosting such events at any time during this academic year given ongoing decisions by other entities."

The big picture: A string of major sports cancellations began Wednesday night with the NBA, which announced it would suspend its season indefinitely after a player on the Utah Jazz tested positive for the coronavirus. The NHL and MLS suspended their seasons on Thursday, and the MLB postponed spring training games.