In an extraordinary move, the NCAA announced Wednesday the men's and women's basketball tournaments will be held as scheduled at all venues next week but without fans present.

NCAA president Mark Emmert said in a statement that he made the unprecendented decision to move the events behind closed doors after consulting with public health officials, in an attempt to slow the spread of the novel coronavirus, which has infected hundreds of people across the United States over the past week.

Attendance at the NCAA tournament events will be limited to essential staff and family members, Emmert said.

"While I understand how disappointing this is for all fans of our sports, my decision is based on the current understanding of how COVID-19 is progressing in the United States," Emmert said in part of the statement. "This decision is in the best interest of public health, including that of coaches, administrators, fans and, most importantly, our student-athletes."

The Associated Press reported that the the NCAA is also attempting to move the Final Four in Atlanta out of Mercedes-Benz Arena, which houses the NFL's Atlanta Falcons, and into a smaller venue. Regional games — like those scheduled to occur in 70,000-seat Lucas Oil Field in Indianapolis — could, in a similar fashion, be moved to smaller venues in their same cities.

"We have to determine the availability of the sites, obviously, but it doesn’t make good sense to have a football stadium be empty," Emmert told AP.

The Division I men's basketball tournament, known colloquially as March Madness, is one of the premier events in college sports — attracting hundreds of thousands of fans and generating millions of dollars in revenue for the NCAA. The 2019 iteration of the event brought in $867.5 million in television and marketing rights alone, according to the NCAA's most-recently audited financial statement.

Now, the 67-game men's tournament will be played in empty arenas at 14 sites throughout the country, beginning Tuesday night with the "First Four" in Dayton, Ohio.

The bracket for the men will be announced Sunday evening. The women, who open on campus sites next weekend, will see their bracket Monday.

Championships in other sports, including hockey's Frozen Four, will also be impacted.

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Several conference basketball tournaments were left scrambling in the wake of the news, as they prepared to host games with fans as usual.

The Southeastern Conference, for example, opened its men's basketball tournament at Bridgestone Arena as planned Wednesday night, with Ole Miss facing Georgia and Vanderbilt playing Arkansas in first-round games. Fans were admitted.

The SEC later issued a statement explaining that it would play behind closed doors, beginning Thursday. The ACC, Pac-12, Big 12 and Big Ten — all of whom had fans at their conference tournaments — made similar announcements.

The changes follow a series of similar measures in several U.S. cities and in sports leagues around the world. In Italy, the government first barred spectators from games before later moving to suspend all sporting events in the country through April 3. In France and Spain, key soccer matches were slated to be played behind closed doors.

The NCAA had, as of Tuesday morning, indicated there would be no changes to its men's and women's basketball tournaments, even as the Ivy League cancelled its conference tournaments before they began and Division III tournament games were played in empty arenas.

That thinking changed, however, as more public officials cautioned against large gatherings of people.

There appeared to be an appreciation of the unique challenges that the NCAA tournament could pose from a public health standpoint — with fans from one part of the country traveling to another, and then convening in close quarters.

The decision to move March Madness behind closed doors represents a new frontier of sorts for American sports, which have never seen an event of this size and scope take place without fans present.

While such a step has been taken on rare occasions due to weather or security-related concerns — including, most notably, a Baltimore Orioles game in 2015 that was played without fans following the death of Freddie Gray — it had never been realistically considered by sports organizations en masse.

It's unclear how players, teams and TV viewers will react to the change. Will the eerie quiet of an empty arena negatively affect a TV broadcast, for example? Andrew Zimbalist, an economics professor at Smith College, certainly thinks so.

"It’s never as much fun to watch a game on television when you’re looking at empty seats in the stands," Zimbalist told USA TODAY Sports last week. "So it could have impacts on television ratings."

CBS and Turner Sports, which share broadcasting rights of the men's basketball tournament, said in a statement they supported the NCAA's decision and "will continue with our plans to fully produce and cover the entire event."

Jim Nantz, who will help broadcast NCAA tournament games on CBS, told reporters on a conference call prior to the news that he hopes the event can help viewers take their minds off the virus.

"This comes at a time where the country really needs more than ever a chance to have something that brings some joy/fun into their lives," he said. "More of an escapism, if you will."

Contributing: USA TODAY Network's Tommy Deas.

Contact Tom Schad at tschad@usatoday.com or on Twitter @Tom_Schad.