ATLANTA — The National Collegiate Athletic Association said Thursday that it had canceled its Division I men’s and women’s basketball tournaments because of the coronavirus pandemic, erasing one the most anticipated annual events on the American sports calendar.

“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 NCAA said in a statement that referred to the illness.

The NCAA initially responded to the outbreak by deciding Wednesday to bar spectators from attending the tournament games in dozens of cities across the country. Its latest move, which came the day after the NBA suspended its season when a player tested positive for the virus, means that the association will be unable to fulfill network broadcast contracts that provide much of its revenue.

Although the NCAA’s president, Mark Emmert, said in an interview Wednesday evening that he thought the limits on fan attendance had left the association in “the right place,” he declined to rule out the possibility of an outright cancellation. Within 24 hours, mounting fears — and a wave of conference tournament cancellations — led the association to scratch the national competitions.

The men’s tournament was expected to begin Tuesday and conclude in Atlanta on April 6, while the women’s tournament was planned to start March 20 and finish in New Orleans on April 5.