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Anthony Petronzio was on the car ride home from a birthday celebration Wednesday night when the news started to come in.

During the trip, about 40 minutes from a nearby restaurant to his home in Brick, New Jersey, Petronzio and his family had shared some jokes about the coronavirus. But as alerts rolled in and texts from friends shared more developments, the tone changed.

"By the time I got home, all the news had gotten out, and it honestly felt like I went into a different world," said Petronzio, 25. "It was honestly crazy."

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It was an hour that changed reality for many Americans.

At 9 p.m. ET, Donald Trump addressed the country and announced a ban on foreign nationals traveling to the U.S. from many European countries. Just minutes earlier, the actor Tom Hanks had published an Instagram post announcing that he and his wife, the actress Rita Wilson, had contracted COVID-19, the illness caused by the virus. Then, at 9:46 p.m., the NBA announced that it had suspended all games indefinitely.

The rush of news drove home that the coronavirus outbreak had moved beyond a small concern or a general nuisance. Until Wednesday, U.S. reaction had remained relatively muted compared to other countries that had taken significant steps to limit personal interaction and travel.

By Thursday, the cascade of cancellations began: baseball, hockey, the NCAA basketball tournaments, Broadway and Carnegie Hall in New York, colleges and school districts around the country. Looking back, Wednesday night felt like the inflection point, after which daily life in the U.S. would no longer feel the same.

Brielle Ashford, 21, a senior at Arizona State University, had just gotten back from spring break and was watching Trump's address from her room as the messages and calls poured in.

"It was just a whirlwind," she said. "I was talking to my friends. I was talking to my parents, aunts calling me about if my school was still going on, what was I doing."

When the story of this is written, the NBA postponement and Tom Hanks diagnosis could very well be the moment the average American began taking coronavirus seriously. The question, of course, is how much worse this will end up being because that took so long — Wesley (@WesleyLowery) March 12, 2020

Leo Alfred's group chats seized on Trump's address in part because of his circumstances. Alfred, 19, is in Barcelona, Spain, on spring break, and the news of the travel ban sent his friends and family scrambling, he said.

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"None of us were really taking it seriously until very recently," he said.

Alfred, who is a sophomore at the University of Minnesota, said he and his friends are now more worried about people close to them.

"It made us all more worried about the people close to us and the people around us who could be more susceptible," he said.

It has been less than three months since reports emerged that a new coronavirus had been identified in the Chinese city of Wuhan and less than two months since the first U.S. case was reported.

Initial reports were met by global health officials with muted concern but serious warnings. As the virus spread to more parts of the world — South Korea, Italy and Iran remain major hot spots — foreign governments moved to take a variety of precautions.

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In the U.S., the response had been muted, leading some health officials to warn that the government was not adequately responding, particularly in terms of testing possible cases. Public officials seemed reluctant to cancel major events and gatherings, balancing the need for safety with the fear of panicking the country.

Delayna Schneider, 37, of Kitsap County, Washington, said that even as coronavirus cases began to grow in the area, many people in her community, particularly Trump supporters, still did not take the problem seriously.

After Wednesday night, she said, she began noticing a difference. Fewer friends were posting memes on social media making light of the coronavirus or the people concerned about the outbreak.

"Certainly they are taking it seriously now," she said. "At the end of the day, it was kind of fortuitous that it happened that way, like bam, bam, bam."

U.S. public interest in the coronavirus began to grow in late January, according to data from Google Trends, which shows what people are looking for in Google's search engine. Searches for "coronavirus" then waned until late February, when interest spiked as more cases were confirmed in the U.S.

By early March, the coronavirus had emerged as one of the most searched-for terms in Google's history. Then Wednesday night happened.