A conference expected to draw 11,000 people to Denver this week — many from other countries — was canceled at the last minute Saturday due to concerns over the spread of COVID-19, the new coronavirus.

The decision to cancel the American Physical Society’s March Meeting, which was scheduled to start Monday, drew criticism from some travelers who were already in Denver or en route when the announcement was made Saturday night.

But American Physical Society’s CEO, Kate Kirby, defended the move, which she said was due “rapidly escalating” developments surrounding the coronavirus disease.

“It is not just our participants we’re looking at,” she said Sunday. “We’re very concerned about the potential of any spread of contagion to the Denver community by having a group of international folks (there) for five days.”

About 800 people had previously canceled their presentations or attendance at the week-long conference, which was to be held at the Colorado Convention Center downtown, before organizers decided to cancel the entire event, Kirby said. About 500 of those cancellations were people who would have been coming from China, she said. Some had made arrangements to give their planned presentations virtually.

Additionally, about 500 people were planning to attend the conference from countries that have put in place some quarantine measures, Kirby said, including South Korea, Japan and Italy. The Centers for Disease Control and Prevention on Saturday afternoon upped its warnings about South Korea and Italy, urging Americans to avoid all nonessential travel there.

Also on Saturday, the first death in the United States from the novel coranavirus was reported in Washington state, and more than 50 people in that area were sick and being tested for the virus. The governor of Washington declared a state of emergency as authorities across the West Coast braced for additional cases.

“The decision was made considering what we felt to be the risk,” Kirby said, “for a five-day meeting and having 5% of the participants coming from countries where there was known active contagion.”

Some people who’d planned to attend the conference expressed frustrations that the event was canceled only 36 hours before it was scheduled to start.

Santiago Nunez-Corrales, a graduate student at the University of Illinois, said he arrived in Denver with his wife around 6 p.m. Saturday. Both had planned to present research at the conference.

The pair had time to grab dinner and head to their hotel before the American Physical Society announced the conference had been canceled around 8 p.m.

“We understand the responsible thing to do was to cancel the conference,” Nunez-Corrales said. “What seems rather inconvenient is the timing.”

He and his wife wanted to return to Chicago as quickly as possible, and on a direct flight, in order to minimize their potential exposure to COVID-19, he said. But they delayed their return until Tuesday because flights before then were between $500 and $800, he said, adding that he believes the conference should have made the call about canceling earlier.

“In my case, I study here in the U.S.,” he said. “It’s not a big deal for travel distance. But many people I know from other countries, they arrived here after several hours of travel to find themselves stranded without having a conference.”

He added that for graduate students, who are often on a tight budget and pay for travel to conferences out of pocket, expecting to later be reimbursed, the cancellation raises uncertainty about whether universities will reimburse expenses when the conference never happened.

The American Physical Society, a nonprofit headquartered in Maryland that works to increase knowledge about physics, said in its statement that it would refund attendees’ registration fees, which ranged between $200 and $700 per person, and that it was looking into whether hotel cancellation fees could be refunded as well.

Kirby apologized for the inconvenience of the cancellation but also said most attendees were expected to arrive Sunday, not Saturday.

Santiago said the organization’s communication with attendees and presenters has been good since the cancellation announcement.

“They’ve demonstrated being responsible and mindful about what happened,” he said.

More than 80,000 COVID-19 cases have been confirmed globally with more than 2,760 fatalities. The respiratory sickness was first detected in Wuhan City, China, and continues spreading to other countries around the world.

Experts in Colorado, where no one has yet tested positive for the disease, said residents would be wise to prepare now by ensuring they have enough medicine, food and water on hand, but also should take regular precautions to avoid getting sick like washing their hands, using hand sanitizers, covering coughs and staying home when sick.

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