(CNN) Perhaps nothing illustrates the wide-ranging effects the novel coronavirus has had on the United States as the state it left major US sports in on Thursday.
By the afternoon, most professional leagues and the governing body of major college sports had canceled or postponed a slew of games and major events. Some elected to go ahead -- without fans in the stands.
"This is time for big events like March Madness, big events like these big sports arena things to take a pause for the next four to six to eight weeks," Centers for Disease Control and Prevention Director Robert Redfield said at a House Oversight Committee hearing in Washington, "while we see what happens with this outbreak in this nation."
Here's a look at the impact on major sports:
The National Basketball Association announced Wednesday night it would suspend its season after a player on the Utah Jazz tested positive for coronavirus.
The first player, identified by ESPN and other outlets as all-star center Rudy Gobert, was later joined by a second Jazz player who tested positive, the team said Thursday.
Initially, the NBA postponed the Jazz's game against Oklahoma Thunder before it announced it would suspend the rest of the season after Wednesday night's games.
"The NBA will use this hiatus to determine next steps for moving forward in regard to the coronavirus pandemic," the NBA said in a statement.
The National Collegiate Athletic Association (NCAA) on Thursday canceled March Madness -- the men's Division I basketball tournament and the biggest annual event in college basketball -- as well as other 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," NCAA said in a statement.
The NCAA previously said March Madness would proceed without any fans, and that only essential staff members and family members would be allowed to attend.
Thursday afternoon, Duke University announced it would suspend all athletic competition.
"I know it is a great disappointment to our student-athletes and coaches, whose hard work and dedication to their sports and Duke is inspirational to so many," said President Vincent E. Price, "but we must first look out for their health and well-being. This is clearly an unprecedented moment for our university, our region and the wider world."
Multiple college conferences also canceled ongoing basketball tournaments, including the Big Ten Conference and the SEC, among others.
Major League Baseball will cancel its remaining spring training schedule and delay Opening Day -- scheduled for March 26 -- back by at least two weeks, the league said Thursday.
"Nothing is more important to us than the health and safety of our players, employees and fans," the league said in a statement. "MLB will continue to undertake the precautions and best practices recommended by public health experts. We send our best wishes to all individuals and communities that have been impacted by coronavirus."
MLB plans to announce the postponement's impacts on the schedule at a later point, "with the hope of resuming normal operations as soon as possible," the statement said.
Major League Soccer will suspend its season for 30 days while it reevaluates the impact of the coronavirus.
"Our clubs were united today in the decision to temporarily suspend our season -- based on the advice and guidance from the Centers for Disease Control and Prevention, Public Health Agency of Canada, and other public health authorities, and in the best interest of our fans, players, officials and employees," MLS Commissioner Don Garber said in a statement. "We'd like to thank our fans for their continued support during this challenging time."
The news came after the Seattle Sounders postponed its home match on Saturday at CenturyLink Field against FC Dallas.
US Soccer canceled games for the Men's and Women's National Teams through April.
"With the health of our players, coaches, staff and fans as our main priority, US Soccer has decided it was in the best interest to cancel the majority of our upcoming domestic and international camps at all levels, including our senior Men's and Women's National Team games in March and April, due to the outbreak of COVID-19," US Soccer Chief Medical Officer George Chiampas said in a statement Thursday.
The USMNT was set to play the Netherlands in two matches later this month, while the USWNT was scheduled to host Australia on April 10 in Sandy, Utah, and Brazil on April 14 in San Jose, California.
The National Hockey League said it would suspend its season, effective immediately.
The league had been preparing for the developments without "taking premature or unnecessary measures," Commissioner Gary Bettman said in a statement.
"However, following last night's news that an NBA player has tested positive for coronavirus -- and given that our leagues share so many facilities and locker rooms and it now seems likely that some member of the NHL community would test positive at some point -- it is no longer appropriate to try to continue to play games at this time," Bettman said.
The PGA Tour announced late Thursday the Players Championship was canceled.
The tour was also canceling all other events in the coming weeks through the Valero Texas Open (March 30 to April 5), it said in a statement.
"We have pledged from the start to be responsible, thoughtful and transparent with our decision process," the Tour said. "We did everything possible to create a safe environment for our players in order to continue the event throughout the weekend, and we were endeavoring to give our fans a much-needed respite from the current climate."
But the situation is rapidly changing, organizers wrote, and "the right thing to do for our players and our fans is to pause."
Augusta National Golf Club said Friday it would postpone the Masters, which was set to tee off on April 9.
"Ultimately, the health and well-being of everyone associated with these events and the citizens of the Augusta community led us to this decision," said Chairman Fred Ridley. "We hope this postponement puts us in the best position to safely host the Masters Tournament and our amateur events at some later date."
NASCAR will hold races at Atlanta Motor Speedway and Homestead-Miami Speedway without fans in attendance, it said in a statement.
"These events will be restricted to competitors, crews, officials and other necessary personnel to conduct the race," the statement said. "We will work with public health officials as we determine future scheduling beyond these events."
The Boston Marathon has been postponed until September 14, Mayor Marty Walsh said Friday. It was scheduled to take place on April 20.
"Our expectation and the hope right now is that this date will get us to a safer place in relation to the spread of the coronavirus," Walsh said.
The Boston Athletic Association, which organizes the race, said in a statement it understood the decision to postpone.
"On matters of public health and safety we take our guidance from the officials entrusted with protecting the public in this area," CEO Tom Grilk said. "We understand our role, along with our partners, in ensuring a safe environment for all participants, volunteers, spectators, and supporters that meets the standards set by those officials."