"All of us really want to stay here and make sure we're all medically clear and the public safe," said Matthew L. McCoy, a theme park designer who lives in China.
McCoy is among the 195 Americans who returned on a charter flight earlier this week from Wuhan, the Chinese city at the center of the outbreak. Initially, health officials asked them to stay at March Air Reserve Base in Riverside for up to three days of monitoring and testing.
On Friday, the government ordered them into quarantine for two weeks. Health officials believe it can take up to two weeks for someone who is infected to get sick. So far there's been no sign of illness.
It was the first federal order since 1963, when a woman was quarantined after she returned from a trip to Sweden during a smallpox outbreak, and she could not prove that she had been vaccinated.
"We understand this action may seem drastic. We would rather be remembered for overreacting than underreacting," said Dr. Nancy Messonnier of the Centers for Disease Control and Prevention.
Later Friday, the government declared a public health emergency and said any other Americans returning to the U.S. from Hubei province, which includes Wuhan, will also be quarantined for two weeks. The State Department is planning more flights to bring Americans out of Wuhan.
McCoy lives in Shanghai but got stuck in Wuhan during a business trip when Chinese authorities shut down the city of 11 million people because of the outbreak. Other evacuees include U.S. government employees and their families.
"Everybody was very relieved" about the quarantine order, McCoy said by telephone. "We wanted to make sure all the tests were done first."
At the military base about 60 miles (97 kilometers) east of Los Angeles, the evacuees are staying in hotel-style housing and have spent time walking and exercising, some wearing masks, said Jose Arballo Jr., a spokesman for the county's public health agency.
As of Friday, none of the evacuees had shown signs of illness, he said. The CDC said test results are still coming in for the group; all have been negative so far.
One person tried to leave the base Wednesday night and was quarantined by the county. The CDC's Dr. Martin Cetron on Friday said that incident did not drive the decision for the federal quarantine.
McCoy said he's been able to keep up with his work in his room on the base and has hooked his computer up to the television screen. Children are outside playing, and everyone is trying to make the experience as easy as possible for each other, he said.
Another evacuee said he had been hoping to get out over the weekend but was OK with the order.
"It's the right thing to do, and I completely understand, and so do a lot of other people here on the base," said Jarred Evans, who moved to Wuhan several years ago to play in a Chinese football league.
"People want to go home. But it's better than being stuck in the epidemic center," he said.
Since December, the virus has sickened thousands, mostly in China. Symptoms include fever, cough and in more severe cases shortness of breath or pneumonia.
There have been seven cases in the U.S., all travelers except for a Chicago man who caught it from his wife, who got sick when she returned home from China.
Evans said Wuhan was like an Old West ghost town when he left.
"Imagine New York City being shut down," he said in an earlier interview. "I was completely scared at first, because I didn't know exactly what was going to happen."