Denver residents on Monday were ordered to stay at home to stop the spread of the coronavirus.

“This isn’t a recommendation anymore. People need to stay at home,” Mayor Michael Hancock said at a press conference. “We will enforce when and where necessary.”

The order begins Tuesday at 5 p.m. and lasts until April 10. By then, Public Health Director Bob McDonald said, city officials will be able to determine whether the spread of the virus, which causes the respiratory illness COVID-19, is slowing.

Hancock’s order places Denver in league with California, Illinois and New York, plus counties and cities across the country with similar restrictions. About one in five Americans are under orders to stay home, the New York Times reports.

Denver has a population of about 2.8 million.

The order closes nonessential businesses and public places in Denver. Residents are required to shelter in their homes, leaving only when they must. Grocery shopping and doctor visits are examples of exemptions to the order.

At first, liquor stores and recreational marijuana shops didn’t make the list of essential businesses. However the city reversed its original decree within hours after would-be shoppers formed lines wrapping around the block for both types of establishments. Now liquor and marijuana stores can remain open with measures in place to ensure 6-foot spacing between individuals.

Argonaut Wine & Liquor co-owner Josh Robinson told the Denver Post that his staff had to act like bouncers, allowing one shopper in for each person that left.

“It’s created a safety issue in the short term,” Robinson said. “The mayor said not to panic-buy, but that is exactly what he encouraged people to do by shutting us down.”

In Colorado, wine and spirits can be purchased only at liquor stores. Beer can be purchased at supermarkets.

Pennsylvania last week closed its 611 state-run wine/spirits stores as a coronavirus mitigation method. On March 17, the last day they were open, the stores had $20.3 million in sales, almost 20 percent more than the previous record set on the day before Thanksgiving in 2019.

Under the Denver order, Denver International Airport will continue to operate. City parks will remain open, but group activities will be prohibited and playgrounds closed.

Hancock said he anticipates other communities in the metropolitan area might issue their own stay-at-home orders, but it appears unlikely Colorado Gov. Jared Polis will do so statewide in the near future. Several hours after Hancock’s statement, Boulder City Manager Jane Brautigam ordered a similar stay-at-home order there along the same timeline.

Instead, Polis on Sunday ordered employers at noncritical workplaces to halve their in-person staffs and asked residents to go out less frequently for groceries and exercise. He also advised the elderly and the otherwise vulnerable to remain indoors unless they need medical attention.

As of Monday afternoon, 148 people in Denver had tested positive for the virus — likely a fraction of those who’ve contracted it, since tests are scarce. No deaths have been reported in the city. Statewide, nearly 720 people have tested positive for the virus and seven have died.

Police and business inspectors will enforce the order, Hancock said, but he’s hoping for voluntary compliance.

“If you’re sick, stay home. If you’re not sick, you need to stay home, too,” he said.