A basketball tournament, with no fans. A St. Patrick's Day, with no parades. College campuses, with no students. Corporate headquarters, with barren cubicles. California's governor urged people to avoid even small social gatherings, if they can't remain six feet apart.

The nation snapped to attention on Wednesday as the new coronavirus was declared a pandemic, stocks slid into bear market territory and the American public finally began to come to grips with the outbreak. The NBA said it would suspend its season until further notice. President Donald Trump held a rare prime-time address from the Oval Office to calm the public.

Health and government officials have been sounding the alarm about the virus for nearly two months as it infected and killed thousands of people, pinballing from China to Iran to Italy and beyond before striking Seattle in the first deadly outbreak in the U.S.

But Wednesday was the moment that the larger American public came to the dawning realization that the toll of the virus would be unavoidable for months to come, perhaps longer.

In the matter of hours Wednesday afternoon, the signs were everywhere. The NCAA announced that the rite of spring for so many Americans — its college basketball tournament — would be played before largely empty arenas. Around the same time, the White House scheduled a nationally televised address. News feeds lit up with cancellations of St. Patrick's Day parades, major university systems in California, New York and elsewhere ending classes for the term and late night comedians making plans to film without live studio audiences.

CBS Evening News anchor Norah O'Donnell solemnly declared during Wednesday evening's broadcast that two employees of the network had tested positive and those who worked closely with them had been asked to self-quarantine.

Later in the day, Hollywood icon Tom Hanks announced that he and his wife have tested positive for the virus. Just as the Hanks news was bouncing around the internet and on people's phones, the NBA said it would pause its season until further notice.

"The NBA will use this hiatus to determine next steps for moving forward in regard to the coronavirus pandemic," the league said in a statement.

In his prime-time address, Trump declared that he is sharply restricting passenger travel from 26 European nations to the U.S. beginning late Friday, at midnight. Trump said the month-long restrictions won't apply to the United Kingdom, and there would be exemptions for "Americans who have undergone appropriate screenings." He said the U.S. would monitor the situation to determine if travel could be reopened earlier.

"We are all in this together," Trump said.

The Oval Office address was an abrupt shift in tone from a president who has repeatedly sought to downplay the severity of the threat, telling people: "It will go away, just stay calm."

Many Americans shared a mindset similar to Trump's in recent weeks, but the events of Wednesday changed the mood.

Koloud 'Kay' Tarapolsi of the Seattle suburb of Redmond learned that two of her children will have to be kept home from school because their district closed for two weeks starting Thursday. Their Girl Scout activities including cookie-selling have already been curtailed.

"We're adjusting," she said. "If we avoid each other and listen to the scientists, maybe in a few weeks it will be better."

California Gov. Gavin Newsom issued among the most sweeping "guidance," urging an end to all events involving more than 250 people, and even small gatherings in spaces that don't allow for "social distancing."

"Not holding that concert or community event can have cascading effects — saving dozens of lives and preserving critical health care resources that your family may need a month from now," Newsom said in a statement late Wednesday.

Newsom's announcement is a recommendation, not a ban like the one Washington Gov. Jay Inslee imposed on all gatherings of 250 or more in Seattle's metro area. The San Francisco Bay Area and other American cities also have banned large gatherings of people, while celebrations including St. Patrick's Day parades in Chicago and Savannah, Georgia, were canceled.

The World Health Organization called the crisis a pandemic, a step it had previously resisted. Stocks plunged, with the S&P 500 on the cusp of falling into bear territory at nearly 20% lower than the record set just last month.

The Seattle Public School system said it would close for at least two weeks for its 53,000 students. COVID-19 has killed more than two dozen in the Seattle area.

Seattle Public Schools Superintendent Denise Juneau called it "an unprecedented situation."

As of Wednesday evening, 38 people had died in the U.S., while more than 1,300 people had tested positive for the new coronavirus.

That's far less than the toll in other parts of the globe: In Italy, where more than 12,000 people had tested positive and 800 people have died, the situation was so dire that all stores except pharmacies and food markets were ordered closed.

For most people, the new coronavirus causes 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 new virus. According to the World Health Organization, people with mild illness recover in about two weeks, while those with more severe illness may take three to six weeks to recover.

Meanwhile, from UCLA to the University of Vermont, the number of colleges and universities canceling in-person classes and moving the rest of the semester online mounted.

In New York City, there have only been a few dozen people diagnosed with COVID-19, but the virus is still all that anyone was talking about.

Subway trains, usually jam-packed at rush hour, were unusually uncrowded Wednesday. City transportation officials reported that the number of people cycling to work in Manhattan over the East River bridges has soared 55% over the past few days as people have heeded the mayor's suggestion to avoid public transportation during peak hours.

Some grocery stores across the city, which ran out of hand sanitizer days ago, have seen shelves empty of other items, like bottled water. Public places have seemed a little less teeming, though tourist hubs like Times Square are still attracting plenty of people.

Late night comedians made plans to start filming without live audiences. NBC's "Late Night With Seth Myers" tweeted it was following guidance by New York City officials.

"We hope to do our part to help to decrease the rate of transmission in our communities," it wrote.

Even email boxes were papered with references to the new virus, as employers wrote to workers outlining new work-from-home procedures, and businesses sent emails to customers with subject lines like "Coronavirus update."

Holly Wagner, 20, a sophomore at New York University, said she had been planning on visiting Washington, D.C., over spring break, but now is worried the campus will shut entirely while she's gone, leaving her unable to retrieve belongings.

"I'm worried the situation is going to escalate and they're going to say, 'don't come back to the dorms,'" she said.

Rhode Island Gov. Gina Raimondo also asked residents not to organize or attend gatherings of more than 250 people, but stopped short of an outright ban. Still, at an afternoon news conference, she pleaded for people sick even with just aches and pains to stay home.

"We understand that people have to live their lives and and business has to continue," she said. "However, we only have one chance to contain this."

___

The Associated Press receives support for health and science coverage from the Howard Hughes Medical Institute's Department of Science Education. The AP is solely responsible for all content.

___

La Corte reported from Olympia, Washington, Smith from Providence. Associated Press writers Adam Geller, David B. Caruso and Theo Wayt in New York; Chris Grygiel in Seattle; Janie Har, Jocelyn Gecker, Olga Rodriguez and Juliet Williams in San Francisco; Robert Jablon in Los Angeles; Lisa Baumann in Seattle; Ken Ritter in Las Vegas; and Ricardo Alonso-Zaldivar and Marilynn Marchione in Washington, D.C., contributed to this report.

___

Follow AP coverage of the virus outbreak at https://apnews.com/VirusOutbreak and https://apnews.com/UnderstandingtheOutbreak