The Big Ten Conference has postponed the 2020 football season because of safety concerns stemming from the novel coronavirus pandemic, the league announced Tuesday. The Big Ten is the first of college football’s elite Power Five conferences to decide against playing football this fall.

After sports halted in March, college athletic departments and their conferences have gradually moved toward returning to competition this fall. But the number of coronavirus cases in the United States began rising in June and multiple schools dealt with outbreaks within their football programs even before formal practices had begun.

The Big Ten’s decision to cancel all fall competition also affects all other fall sports — men’s and women’s soccer, men’s and women’s cross-country, field hockey and women’s volleyball. The conference said it will continue to evaluate options regarding these sports, including the possibility of playing in the spring. The Big Ten has not made a decision regarding winter sports, such as men’s and women’s basketball, which begin their seasons in November.

“The mental and physical health and welfare of our student-athletes has been at the center of every decision we have made regarding the ability to proceed forward,” Big Ten Commissioner Kevin Warren said in a statement. “As time progressed and after hours of discussion with our Big Ten Task Force for Emerging Infectious Diseases and the Big Ten Sports Medicine Committee, it became abundantly clear that there was too much uncertainty regarding potential medical risks to allow our student-athletes to compete this fall.”

With the Big Ten’s decision, 41 of the 130 FBS schools have either said they will not play this fall or are in conferences that have made that decision. The Mid-American Conference postponed its football season Saturday, becoming the first league to do so in the Football Bowl Subdivision, the top tier of college football. The Mountain West Conference followed Monday, canceling all fall sports.

In addition, the University of Massachusetts, an FBS independent in football, announced on Tuesday that it was canceling its season. Last week, the University of Connecticut became the first FBS program to shut down its 2020 season, which would have been its first as an independent. Old Dominion, a member of Conference USA in most sports including football, canceled all fall sports Monday.

Players, coaches, lawmakers and President Trump expressed support for playing this fall, while others have doubted that they can practice and play safely amid a pandemic. Because college football players are amateurs, they do not have a players’ union that makes them a formal part of the decision-making process. As uncertainty about the season grew in recent days, many players and coaches publicly pushed for playing this fall.

“Our university is committed to playing no matter what, no matter what that looks like and how that looks,” Nebraska Coach Scott Frost told reporters Monday afternoon. “We want to play no matter who it is or where it is. So we’ll see how all those chips fall. We certainly hope it’s in the Big Ten. If it isn’t, I think we’re prepared to look for other options.”

The Big Ten’s decision could ripple across college football as other conferences engage in similar conversations about whether a season can be safely held. The Big Ten, which consists of 14 schools spanning 11 states, was the first of the Power Five conferences to announce an adjustment to its 2020 football season by shifting to a conference-only schedule. The Pac-12 and SEC followed suit with the same plan, while the Big 12 and ACC decided to keep one nonconference game on each school’s schedule.

The broadcast rights for football generate millions of dollars for the Big Ten’s athletic departments, and schools across the country have projected major deficits in the wake of the pandemic. Wisconsin, for instance, recently announced a fundraising campaign that said the athletic department expected to face a revenue shortfall of more than $100 million if the season was canceled and a deficit of $60 million to $70 million if the team played with limited fans. Frost said Nebraska’s athletic department would suffer a hit of $80 million to $120 million without a football season. In many athletic departments, the revenue from football covers the operating costs of all the nonrevenue programs the school offers.

As the Big Ten moved toward football season, which was set to begin the weekend of Sept. 5, the conference developed guidelines to limit the risk of playing. During the season, the Big Ten planned to test athletes and personnel twice a week. Anyone who had been in close contact with someone who tested positive for the coronavirus had to quarantine for 14 days — an effective measure in controlling the spread of the virus but one that sounded alarms about the feasibility of a season. Through contact tracing protocols, even a small number of positive cases on a team could require a large chunk of players to sit out for two weeks.

While Warren has expressed confidence in the conference’s health and safety protocols, he hasn’t shied away from acknowledging the uncertainty around holding a football season this fall.

“We may not have sports in the fall,” Warren said in July after the Big Ten announced its plan for conference-only schedules. “We may not have a college football season in the Big Ten.”

When the conference announced each team’s week-by-week schedule a month later, Warren repeated the sentiment: “There’s no guarantee that we will have fall sports or football season.”

By Tuesday, six days after those schedules were released, the Big Ten canceled the fall season, a decision voted on by the conference’s university presidents. When asked on the Big Ten Network, Warren would not say whether the vote was unanimous.

Football players returned to campuses in June for voluntary workouts held in small groups. Michigan State and Rutgers each had to quarantine their entire team after a spike in cases inside their programs. Big Ten teams resumed practice last week, but the conference announced Saturday morning that, until further notice, football players could only practice with helmets and no pads. With four weeks until the start of the season, the conference’s statement said, “We understand there are many questions regarding how this impacts schedules, as well as the feasibility of proceeding forward with the season at all.”

Unlike in professional sports, college football programs cannot keep their players inside an insular environment that limits contact with the public. Instead, these athletes would have, in some cases, attended in-person classes with their peers before congregating with their teammates for meetings and practices.

Football players from the Pac-12, Big Ten and Mountain West released statements asking their conferences for improved health protocols. More than 30 Power Five football players, including at least 13 from the Big Ten, have already chosen to opt out of the 2020 season. The long-term effects of the virus are still unknown, and health experts are worried about how covid-19, the disease caused by the coronavirus, affects the heart.

Players from the Power Five schools, including Clemson quarterback Trevor Lawrence and Ohio State quarterback Justin Fields, shared a unified message on social media Sunday night with the hashtag #WeWantToPlay. Trump retweeted Lawrence’s post and added: “The student-athletes have been working too hard for their season to be cancelled. #WeWantToPlay.”

Multiple Big Ten coaches publicly expressed their desire to play this fall. Ohio State football coach Ryan Day tweeted Monday afternoon: “Swinging as hard as we possibly can right now for these players!! This isn’t over!” The official Twitter accounts for Ohio State football and Michigan football retweeted multiple posts from players and coaches who were in favor of a fall season.

But university presidents, who leaned on medical professionals for advice, ultimately made this decision. And for those Big Ten leaders, the risks of a virus that the country has yet to contain were enough to topple the season.