The Grand Princess cruise ship sits off the coast of San Francisco, Mar. 8, 2020. The Grand Princess cruise ship set to dock at the Port of Oakland in California on Monday. Some 19 crew members and two passengers have tested positive for the coronavirus, and all the passengers will now have to undergo quarantine. Twenty Chinese nationals including 11 crew members and nine passengers are on the ship. (Photo: China News Service/ Liu Guanguan)

The Grand Princess cruise ship sits off the coast of San Francisco, Mar. 8, 2020. The Grand Princess cruise ship set to dock at the Port of Oakland in California on Monday. Some 19 crew members and two passengers have tested positive for the coronavirus, and all the passengers will now have to undergo quarantine. Twenty Chinese nationals including 11 crew members and nine passengers are on the ship. (Photo: China News Service/ Liu Guanguan)

The Grand Princess cruise ship sits off the coast of San Francisco, Mar. 8, 2020. The Grand Princess cruise ship set to dock at the Port of Oakland in California on Monday. Some 19 crew members and two passengers have tested positive for the coronavirus, and all the passengers will now have to undergo quarantine. Twenty Chinese nationals including 11 crew members and nine passengers are on the ship. (Photo: China News Service/ Liu Guanguan)

The Grand Princess cruise ship sits off the coast of San Francisco, Mar. 8, 2020. The Grand Princess cruise ship set to dock at the Port of Oakland in California on Monday. Some 19 crew members and two passengers have tested positive for the coronavirus, and all the passengers will now have to undergo quarantine. Twenty Chinese nationals including 11 crew members and nine passengers are on the ship. (Photo: China News Service/ Liu Guanguan)

The Grand Princess cruise ship sits off the coast of San Francisco, Mar. 8, 2020. The Grand Princess cruise ship set to dock at the Port of Oakland in California on Monday. Some 19 crew members and two passengers have tested positive for the coronavirus, and all the passengers will now have to undergo quarantine. Twenty Chinese nationals including 11 crew members and nine passengers are on the ship. (Photo: China News Service/ Liu Guanguan)

The Grand Princess cruise ship sits off the coast of San Francisco, Mar. 8, 2020. The Grand Princess cruise ship set to dock at the Port of Oakland in California on Monday. Some 19 crew members and two passengers have tested positive for the coronavirus, and all the passengers will now have to undergo quarantine. Twenty Chinese nationals including 11 crew members and nine passengers are on the ship. (Photo: China News Service/ Liu Guanguan)