(CNN) On Tuesday at Aldercrest, they were disinfecting the saltshakers. The front door was locked. Somewhere outside, a new virus proliferated. It had killed at least 24 people in Washington state, at least 19 at the Life Care Center across the lake. And so, at Aldercrest, another skilled-nursing facility in Edmonds, they were taking precautions.

Visitors had to ring the bell. A nurse wore gloves and held a thermometer. Anyone above 100.3 degrees Fahrenheit would be turned away.

It is a frightening time in America. People have questions about the novel coronavirus . Can they get it from paper money or the swimming pool? Can they kill it with lemons and vinegar? Should they put their gloves in the freezer? "What do I do if I contract the coronavirus and I'm uninsured," someone wrote to CNN. "Am I as good as dead?"

This much is certain: The older and sicker you already are , the more likely it is to kill you. Roughly 2.5 million Americans live in nursing homes and assisted-living facilities. They are in mortal danger

The Covid-19 virus can give a person fever, dry cough, labored breathing. It can also infect you while causing none of those symptoms, which means you might walk around for days as an unwitting carrier. With one sneeze, you could put your grandmother in peril.

All this has put enormous pressure on the people who operate the nation's nursing homes. It is their job to keep the frail and the elderly alive. Now in some cases, that means keeping them away from the ones they love.

The Department of Veterans Affairs on Tuesday banned visitors from its nursing homes . A group that represents 13,000 nursing sites around the country suggested they all do the same. For the elderly, its director said, "Covid-19 is almost a perfect killing machine."

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The Evangelical Lutheran Good Samaritan Society, one of the nation's largest senior-housing providers, also halted visits, with rare exceptions. At its facility in Blaine, Washington, about 110 miles north of Seattle, administrator Haley Amundson said employees were cleaning door handles and water fountains up to three times a day.

Amundson is only 26, and in a phone interview she recalled volunteering in nursing homes as a child. Now, she has been avoiding public events, washing her hands frequently, doing whatever she can to evade the coronavirus. Families had been notified of the new policy, and Amundson said they understood, although she felt sorry for one particular resident who would probably miss having lunch with his wife.

"It's quieter," she said of the facility, which is licensed for 57 residents. They tried to stay at least 6 feet apart while playing bingo. Some stayed in their rooms and strained to hear the activities assistant calling out the numbers.

'To just wholesale lock people out doesn't make any sense'

Across the country in New York, at the Long Term Care Community Coalition, executive director Richard Mollot read the latest news with a skeptical eye. That was part of his job. He didn't see why nursing homes had to ban visitors. After all, it wasn't a true quarantine. Workers came and went all the time, subject to questions and temperature readings and so forth, and he thought visitors should be allowed to do the same.

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"To just wholesale lock people out doesn't make any sense," he said, because residents would miss their loved ones and would need their outside personal-care assistants and would get better care if workers knew that someone was checking on them.

On an issue like this one, reasonable people could disagree. Mollot worried that nursing homes were becoming more like prisons.

The worst-case scenario is fresh in the collective memory. Someone brought the coronavirus into the Life Care Center of Kirkland, Washington, and it spread, and people were dying, and their loved ones could not reach them. On March 1, Bonnie Holstad stood outside, holding a handwritten sign

My husband is a patient

Ken Holstad Rm 50

No one at Life Care is answering the phones. I cannot reach the nursing stations. He now has a cough. He has Parkinson's with dementia. I am his advocate. He needs to be attended to...what is his temperature? Can he be tested for Covid 19?

Bonnie Holstad holds a sign explaining concern for her husband.

and called her mother, Elaine, who said her roommate was coughing. Pat Herrick found out about the quarantine at Life Care Centerand called her mother, Elaine, who said her roommate was coughing.

"I don't know when I'm gonna get to see you again," her mother said on the phone. That was their last conversation before her mother died.

Despite the restrictions, Kim Frey found a way in . Afraid that her 89-year-old mother would die alone, she stood outside the window, holding a sign that said something like, "We can't come in, but Jesus can." A staff member saw her outside and let her in, Frey told the Seattle Times

She wore a mask and visited her mother. But later she began to wonder whether she should have stayed away. If the coronavirus could go into a nursing home, it could also come out.

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"We did just find out that my brother tested positive," she said March 4 on CNN. "My sister is very sick. I have another brother that was sick."

On Wednesday in New Rochelle, New York, the National Guard worked to contain what appeared to be the largest cluster of coronavirus cases in the nation. Not far from the containment area , nearly 500 residents went about their business at the nursing home and assisted-living pavilions of United Hebrew of New Rochelle.

"We're ready for this," said Rita Mabli, the president and CEO.

The governor had banned visitors , but workers were helping residents use iPads to Skype or FaceTime with loved ones. Residents played bridge or poker. A therapist played the guitar.

Gloria Selden, age 91, kept a bottle of Purell in her apartment. She had recently heard about the coronavirus on MSNBC, but her friends weren't talking about it much. They preferred to talk about politics.

Then again, she did understand the risks. Last week, before the ban took effect, her daughter planned to visit from Manhattan.

She would have taken the train.

She would have taken a taxi.

Selden thought about it, and told her to stay away.