KISSIMMEE, Fla. — The NBA’s restart inside a restricted bubble at Disney World, which has proceeded smoothly for more than a month without any positive novel coronavirus tests, came to a screeching halt Wednesday when the Milwaukee Bucks refused to take the court for a playoff game against the Orlando Magic to protest the police shooting of Jacob Blake in Kenosha, Wis. The league announced the cancellation of all three games scheduled for Wednesday as a result, and a meeting of NBA players later Wednesday night cast doubt on whether the postseason would continue at all.

The unprecedented decision to postpone the games was quickly followed by a similar decision by the WNBA, which postponed three scheduled games across the state in Bradenton, and by teams and players in numerous other professional sports.

In Milwaukee, the Brewers announced they would not play their Major League Baseball game Wednesday night against the Cincinnati Reds. The Seattle Mariners’ game against the San Diego Padres and the Los Angeles Dodgers’ game against the San Francisco Giants also were postponed.

The cancellations underscored an emerging new reality in big-time sports in which athletes are increasingly emboldened to express themselves on racial injustice and other social issues and leagues are finding ways to accommodate their views.

Tensions inside the bubble have mounted over the past two days, with players and coaches outraged by the video of Blake’s shooting, but the Bucks’ decision not to play in Game 5 of their first-round series caught league and team staffers by surprise.

Bucks guard George Hill was among multiple NBA players to question whether games should continue considering the ongoing social justice protests around the country, and members of the Toronto Raptors and Boston Celtics discussed sitting out the first game of their second-round series scheduled for Thursday.

Instead, the Bucks went first. Shortly before the scheduled 4:10 p.m. tip Wednesday, the Magic took the court for warmups like usual. The Magic was never joined by the Bucks as arena staffers, ballboys and the referees milled around the court. As the game clock ticked down toward the customary pregame introduction period, the Magic left the court, returned to its locker room and eventually departed Advent­health Arena at the ESPN Wide World of Sports Complex.

The Bucks’ players, who were dressed in their game uniforms as if they had arrived at the arena ready to play, remained inside the locker room with their coaches, General Manager Jon Horst and other team personnel for more than three hours before emerging to demand justice for Blake from Wisconsin politicians.

“When we take the court and represent Milwaukee and Wisconsin, we are expected to play at a high level, give maximum effort and hold each other accountable,” Hill said, reading a statement on behalf of the Bucks players. “We hold ourselves to that standard, and in this moment we are demanding the same from lawmakers and law enforcement. We are calling for justice for Jacob Blake and demand the officers be held accountable. For this to occur, it’s imperative for the Wisconsin state legislature to reconvene after months of inaction and take up meaningful measures to address issues of police accountability, brutality and criminal justice reform.”

The National Basketball Players Association held a meeting Wednesday night to discuss next steps, including whether to continue play or to cancel the balance of the postseason, which is scheduled to run through mid-October. Coaches were invited to a portion of the meeting, which was held in a Disney World ballroom, before the players met among themselves.

The Los Angeles Lakers and Los Angeles Clippers, two of basketball’s top contenders, voted against finishing the postseason at the meeting, according to people with knowledge of the situation, while a majority of the teams present voted to continue. The NBA has a Board of Governors meeting scheduled for 11 a.m. Thursday morning to determine its next steps and attempt to salvage the playoffs. There are three games scheduled for Thursday, but it wasn’t immediately clear whether those would be postponed. The Athletic first reported the meeting’s voting results.

“Throughout the season restart, our players have been unwavering in their demands for systemic justice,” union chief Michele Roberts said in a statement before the meeting. “This week we witnessed another horrific, shocking and all too familiar act of brutality in the shooting of 29 year-old Jacob Blake in Kenosha, Wisconsin. The players have, once again, made it clear — they will not be silent on this issue. We stand with the decision of the players of the Milwaukee Bucks to protest this injustice and support the collective decision to postpone all of today’s games.”

NBA players have been outspoken on the issues of police brutality and racial injustice and have used their platform to express them from inside the bubble set up by the league at the Disney World resort in the midst of the coronavirus pandemic. “Black Lives Matter” is painted in bold letters on the courts, and players are wearing words and phrases calling for social justice on the backs of their jerseys.

But the sentiment has pivoted to anger and despair since the Blake shooting Sunday night. Lakers forward LeBron James issued a powerful postgame statement Monday, saying, “Quite frankly, it’s just f---ed up in our community.”

James’s remarks were followed Tuesday by Clippers Coach Doc Rivers, who said, “It’s amazing why we keep loving this country and this country does not love us back.”

“I commend the players on the Bucks for standing up for what they believe in, coaches like Doc Rivers, and the NBA and WNBA for setting an example,” former president Barack Obama wrote on Twitter. “It’s going to take all our institutions to stand up for our values.”

Before the Bucks’ players addressed a small group of media members, the organization’s ownership group issued a statement backing their decision not to play.

“We fully support our players and the decision they made,” Bucks owners Marc Lasry, Wes Edens and Jamie Dinan said. “Although we did not know beforehand, we would have wholeheartedly agreed with them. The only way to bring about change is to shine a light on the racial injustices that are happening in front of us. Our players have done that and we will continue to stand alongside them and demand accountability and change.”

Numerous NBA franchises, including the Lakers, issued their own statements of support for the Bucks.

The Bucks franchise has had multiple incidents with police brutality and racial profiling in recent years. Bucks guard Sterling Brown sued the city of Milwaukee after he was injured during an incident with police, and former center John Henson spoke out publicly after he was denied service by a Milwaukee jeweler.

“Over the last few days in our home state of Wisconsin, we’ve seen the horrendous video of Jacob Blake being shot in the back seven times by a police officer in Kenosha and the additional shooting of protesters,” Brown said, reading from a statement. “Despite the overwhelming plea for change, there has been no action, so our focus today cannot be on basketball.”

A group of Bucks players turned out for a July protest in Milwaukee with T-shirts that bore some of George Floyd’s last words, “I can’t breathe.” Brown, Donte DiVincenzo, Brook Lopez, Frank Mason III, reigning MVP Giannis Antetokounmpo and his brother Thanasis joined the crowd.

Wisconsin Attorney General Josh Kaul (D) held a brief phone call with the Bucks on Wednesday to explain how the Wisconsin process works. Kaul’s agency is investigating Blake’s shooting, and he held a news briefing Wednesday to offer an update on his ongoing investigation and identify the Kenosha police officer involved.

“I commend the Bucks and now all NBA teams that suspended their games today for stepping up and participating in the dialogue about these issues and making their voices known,” Kaul said at the briefing.

Milwaukee’s other pro team quickly followed the Bucks’ lead as MLB’s Brewers, who like the Bucks play not far from Kenosha, decided they would not play against the Reds, who agreed to sit out.

“Given the pain in the communities of Wisconsin and beyond following the shooting of Jacob Blake, we respect the decisions of a number of players not to play tonight," MLB said in an unattributed statement. “Major League Baseball remains united for change in our society and we will be allies in the fight to end racism and injustice."

Brewers outfielder Ryan Braun told reporters the Bucks had “inspired” them.

“Our team and the Reds felt that with our community and our nation in such pain, tonight we wanted 100 percent of the focus to be on issues that are much more important than baseball,” Brewers pitcher Brent Suter, the team’s MLB Players Association representative, told reporters.

In San Diego, the Seattle Mariners, who have more Black players than any team in the sport, voted unanimously to sit out their game against the Padres, outfielder Dee Gordon said on Twitter.

Later, the San Francisco Giants and Los Angeles Dodgers elected not to play. Dodgers outfielder Mookie Betts, one of the game’s brightest stars, said he would not have played had the game taken place. In contrast to teams who played on while Black players sat out, the Dodgers decided if Betts chose not to play, they would follow him, pitcher Clayton Kershaw said.

“I’ll always remember this day and I’ll always remember this team having my back,” Betts said.

As if to underscore the prominent role athletes have in raising societal awareness of police brutality and racial injustice, the players’ strike came on the four-year anniversary of the first time former NFL quarterback Colin Kaepernick did not stand for the national anthem in protest.

On Tuesday, the Detroit Lions canceled practice and players addressed reporters huddled around a whiteboard reading, “The World Can Not Go On.” On Wednesday night, Washington Football Team Coach Ron Rivera announced Thursday’s practice was postponed, and several NFL players expressed support for the Bucks on social media.

“NBA is showing us how it’s done,” wrote Houston Texans wide receiver Kenny Stills, who has frequently knelt during the national anthem. “Time to connect with local activists to help formulate demands.”

“I don’t think it’s surprising it has spread to other leagues,” Harry Edwards, a sociologist who in 1968 organized the Olympic Project for Human Rights, said in a phone conversation. "[NFL Commissioner Roger Goodell] has to be blind not to see he has some issues here that he’s going to have to deal with up front with the players. This one could spread very, very rapidly, especially if there’s yet another killing between now and the opening of the NFL season, which in my estimation is not unlikely. That’s what we’re up against here.”

All but one of the six Major League Soccer matches were postponed after one or both teams decided not to play. The only one to commence as scheduled was Nashville SC at Orlando City.

The start of the Atlanta-Miami game in Fort Lauderdale, Fla., was delayed 20 minutes before being postponed. The players and referees gathered in solidarity at midfield. The same scene played out in Utah, where Real Salt Lake had been scheduled to host Los Angeles FC.

Before the first game of the MLS tournament at Disney World this summer, more than 100 players participated in a demonstration protesting racial inequality and supporting social justice causes. Throughout the month-long competition, players and coaches wore “Black Lives Matter” T-shirts and wore messages on their game jerseys.

Naomi Osaka, a two-time Grand Slam tennis champion, announced that she would not play her semifinal match in the Western & Southern Open in New York, a U.S. Open tuneup, hours after winning her quarterfinal. A few hours after Osaka’s announcement, the sport’s organizers said play at the event would be paused Thursday and would resume Friday. Osaka’s announcement came with some heft; the 22-year-old is the highest-paid female athlete in the world, having brought in more than $37 million in prize money and endorsements last year, and she has been outspoken on social justice issues all summer.

“I don’t expect anything drastic to happen with me not playing, but if I can get a conversation started in a majority White sport I consider that a step in the right direction,” Osaka wrote on Twitter. “Watching the continued genocide of Black people at the hand of the police is honestly making me sick to my stomach.”

The NHL was not aware of any plans to postpone the league’s remaining Wednesday night playoff games, NHL deputy commissioner Bill Daly told Sportsnet, instead holding “a moment of reflection” in Blake’s honor before the Tampa Bay-Boston game in Toronto and the Colorado-Dallas game in Edmonton.

“I don’t expect the league to initiate a game stoppage,” Daly said. “Obviously, our players are free to express themselves in any manner they feel is appropriate."

Mark Berman, Adam Kilgore, Samantha Pell, Steven Goff and Ava Wallace contributed to this report.