Mark Few reacts to the NCAA tournament being canceled as the news breaks while speaking with Rece Davis. (1:40)

The NCAA canceled its men's and women's basketball tournaments on Thursday because of the spread of the coronavirus, putting an abrupt end to the season less than a month before champions were to be crowned.

The unprecedented move comes a day after the NCAA announced the games that were scheduled to start next week would go on but be played in mostly empty arenas. That plan was scrapped as every major American sports league from the NBA to MLB put the brakes on its season due to concerns about the pandemic.

"This decision is based on the evolving COVID-19 public health threat, our ability to ensure the events do not contribute to the spread of the pandemic and the impracticality of hosting such events at any time during the academic year given the ongoing decisions by other entities," the NCAA said in statement.

The NCAA canceled championships in all spring sports, including hockey, baseball and lacrosse.

Canceled NCAA championships Along with men's and women's basketball, these were the other remaining 2020 Division I winter and spring championships: Baseball

Beach volleyball

Bowling

Fencing

Golf (men's and women's)

Gymnastics (men's and women's)

Ice hockey (men's and women's)

Indoor track and field

Lacrosse (men's and women's)

Men's volleyball

Outdoor track and field

Rifle

Rowing

Skiing

Softball

Swimming and diving (men's and women's)

Tennis (men's and women's)

Women's water polo

Wrestling

The stunning end to the basketball season came about four hours after a frantic morning when conference tournaments around the country came to a sudden halt. Moments away from tipoff at some arenas, and minutes apart, each Power 5 conference canceled its remaining games.

At Madison Square Garden in New York, the Big East game between Creighton and St. John's did start, but at halftime the conference called off that game and all the rest. That turned out to be the last Division I basketball game played this season.

"This has been the most extraordinary stretch of days I've ever had or ever seen in my 30-plus years of working in the sports business," Big East commissioner Val Ackerman said.

Smaller conferences followed suit, shutting down their tournaments, and within a few hours 58 men's games scheduled in 16 conferences had been canceled.

Then the conferences began shutting down all athletic activities, for at least a few weeks (the Southeastern Conference) or indefinitely (the Atlantic Coast Conference).

A few hours later, the NCAA put an end to it all.

"So you telling me I transferred to not play in the tournament," tweeted Gonzaga point guard Ryan Woolridge, a graduate transfer from North Texas. Gonzaga was expected to be a No. 1 NCAA tournament seed and play a possible second-round game in its home city of Spokane, Washington.

The decision to cancel baseball and softball also drew a sharp response from SEC commissioner Greg Sankey.

"Surprised that we've made a decision now in mid-March to not play baseball or softball national championship events [scheduled for June]. So I look forward to learning what informed that decision. I know what's informed our decisions over the last day and a half or so, but the news from the NCAA we were waiting on -- on the basketball tournaments and some of the championships happening now -- but obviously, there was the decision to go further," Sankey said on The Paul Finebaum Show.

For most people, the coronavirus is believed to cause only mild or moderate symptoms, such as fever and cough. For some, especially older adults and people with existing health problems, it can cause more severe illness, including pneumonia. The vast majority of people recover from the virus. Social distancing, which includes canceling events that draw large crowds, is designed to slow the transmission of the disease.

The NCAA men's basketball tournament has been played every year since 1939, when Oregon won the championship in Evanston, Illinois. It has grown through the years, both in size and stature. The three-week tournament generates almost a billion dollars in revenue each year for the NCAA and its hundreds of member universities and colleges, most coming from a television contract with CBS and Turner that pays the NCAA almost $800 million annually.

It is now one of the biggest events in American sports, a basketball marathon of buzzer-beaters, upsets and thrills involving 68 teams. The field for the men's tournament was scheduled to be announced Sunday, creating the famous bracket that sports fans would obsess over in office pools and at sportsbooks.

"While we are obviously disappointed that our season has ended abruptly, we also recognize that this decision was made for a greater good," said coach Casey Alexander, who led Belmont, a private university with 6,000 students in Nashville, Tennessee, to the Ohio Valley Conference championship and a spot in the NCAA tournament earlier this week.

"I respect the NCAA's decision to put everyone's safety first," Arizona State coach Bobby Hurley tweeted. "That said, every team deserves recognition for their season's success. Brackets should still be announced on Selection Sunday."

Some coaches weren't so tempered with their response.

Love for the @NCAA to come look in the eyes of my players right now. You have ripped the heart and soul out of these guys! Why are you cancelling season so prematurely? Can we suspend the season 2-4 weeks and see what happens? We play an outside sport with little spectators! — Greg Sands (@Sandsman14) March 12, 2020

East Tennessee State men's basketball coach Steve Forbes, whose team won the Southern Conference tournament Monday, suggested his seniors should get another year of eligibility.

"I'm heartbroken for everyone associated with our program, especially our five seniors," Forbes said. "[These] young men dedicated their lives to have the opportunity to represent ETSU in the NCAA tournament and it's now been taken away from them at no fault of their own. While I wholeheartedly support this decision, I would like to be a part of the conversation, in conjunction with the Southern Conference and the NCAA, in giving our five seniors another year of eligibility, so they once again have the opportunity turn their dreams into reality by having the chance to play in the NCAA tournament next year. I want to personally thank my team and our fans for the magical season that has now come to an end."

The 64-team women's field was to be revealed Monday.

"This is a difficult time with so many conflicting emotions," Dawn Staley, coach of the No. 1-ranked South Carolina women's basketball team, said in a statement. "First and foremost, we have to recognize how important it is to do the right thing for our community. Sports is a big part of our lives, but just one part of how we are connected to each other. We need to step back and think about the larger good served by canceling events that put people at risk.

"As competitors, we are certainly disappointed that we will not have the opportunity to contend for a second National Championship. That said, it will not diminish the way we look at our season, how we value our body of work over the last four months. We have measured ourselves against the best in the country over that time, and will embrace and relish that accomplishment."

The NCAA women's tournament began in 1982 and it, too, has become a big event, raising the profile of the sport.

"I'm disappointed, but I totally understand. I really feel for the senior student-athletes; every student-athlete, but particularly the seniors because this is their last chance for the fans," said Oregon women's coach Kelly Graves, whose team would have entered the tournament as a favorite to reach the Final Four in New Orleans. "There's something more important than the games going on. I've kind of come to grips to that a little more than a few hours ago."

Games would have started on the men's side on Tuesday in Dayton, Ohio, before spreading out to eight sites from coast to coast from next Thursday through Sunday. The women's tournament was scheduled to begin March 20, with first- and second-round games to be played at 16 sites on or near the campuses of the top teams.

For Baylor, the potential was there for two national championships. The Bears are ranked fifth in the latest men's AP Top 25 and the women's team is No. 2 and the defending NCAA champion.

"I'm overwhelmingly disappointed that our team won't have the opportunity to finish what was arguably the best season in program history," Baylor men's coach Scott Drew said. "We were No. 1 for five weeks and were likely going to get a No. 1 seed in the NCAA tournament, which is something we've worked for all season. To have that opportunity abruptly taken away by something out of our control is devastating for our team, coaches and fans.

"At the same time, we will keep perspective on life's greater challenges, continue to focus on using our platform to honor God, and we'll keep everyone affected by this situation in our thoughts and prayers."

The men's Final Four was to be played April 4 and 6 at Mercedes-Benz Stadium in Atlanta. The semifinals and final typically pack football stadiums for the games, and after the champion is crowned, the best moments of the year's tournament are wrapped up into the "One Shining Moment" montage that has become a staple of CBS' television coverage through the years.

Instead, March Madness took on a different meaning as sports have virtually shut down.

Baseball's College World Series won't be held for the first time since 1946. Omaha, Nebraska, has hosted the Division I baseball championship every year since 1950. The CWS has a $70 million annual impact on the local economy each year and produces 10 days of programming inventory for ESPN.

"Devastating. Stunning," UCLA baseball coach John Savage said. "I feel for all the players. I feel for the coaches. I feel for all the programs that work so hard through the fall and January."

The eight-team College World Series is held each June at TD Ameritrade Park and is the culmination of the NCAA baseball tournament, the No. 2 revenue producer for the NCAA. The event draws more than 300,000 fans per year from across the country and is one of Omaha's most anticipated events of the year.

"To have such a decision to go down so quickly is just really hard to imagine," Savage said. "I feel for the seniors across the country. It's just a really, really sad day."

Information from The Associated Press was used in this report.