SAN FRANCISCO, United States (AP) — Federal and state officials in California prepared to receive thousands of people Monday from a cruise ship that has been idling off the coast of San Francisco with at least 21 people aboard infected with the coronavirus.

Personnel covered head to toe in protective gear woke up passengers on the Grand Princess to check whether they were sick.

Michele Smith, of Paradise, California, said a doctor knocked on her and her husband’s cabin before dawn and asked if they had a fever or a cough. The couple who went on the cruise to celebrate their wedding anniversary are healthy and, like the rest of the 2,400 passengers aboard, have been isolating in their cabins since Thursday.

On land, fences were installed at an 11-acre site at the Port of Oakland as authorities readied flights and buses to whisk the passengers aboard the ship to military bases or their home countries for a 14-day quarantine. The more than 3,500 passengers and staff on the ship hail from 54 countries.

“We’re making every effort to get them off the ship as safely and quickly as possible,” said Dr John Redd of the US Department of Health and Human Services, who urged passengers to remain in their rooms.

As the US death toll from the virus reached at least 21 and the number of cases worldwide soared above 110,000, California Gov Gavin Newsom and the mayor of Oakland sought to reassure the public that none of the Grand Princess passengers would be exposed to the US public before completing the quarantine. The number of infections in the United States climbed above 500 as testing for the virus increased.

The Port of Oakland was chosen for docking because of its proximity to an airport and a military base, Newsom said. US passengers will be transported to military bases in California, Texas and Georgia, where they’ll be tested for the COVID-19 virus and quarantined.

About 1,100 crew on the ship, 19 of whom have tested positive for the new virus, will be quarantined and treated aboard the ship, which will dock elsewhere, Newsom said.

“That ship will turn around — and they are currently assessing appropriate places to bring that quarantined ship — but it will not be here in the San Francisco Bay,” he said.

Dr Anthony Fauci, the National Institutes of Health’s infectious diseases chief, said Sunday that widespread closure of a city or region, as Italy has done, is “possible.” US Surgeon General Jerome Adams said communities will need to start thinking about cancelling large gatherings, closing schools and letting more employees work from home, as many companies have done in the Seattle, Washington, area amid an outbreak at a care home that has killed 17.

On the Grand Princess, the Smiths said they hope their time spent in quarantine on the ship will count toward the 14 days they are expected to isolate themselves. But they said officials have not yet provided an answer.

“We would love to get credit for the three or four days we’ve spent in our cabin,” Steven Smith said.

The Department of State was working with the home countries of several hundred passengers to arrange their repatriation, including nearly 240 from Canada.