The mayor of San Francisco has ordered new lockdowns and business restrictions in the face of the Covid-19 surge.
The new measures announced by Mayor London Breed, a first-term Democrat, are among the harshest of any major US city, closing all personal services, outdoor dining and most public gatherings.
Indoor dining and drinking has been banned across California since mid November.
"What we are seeing in our city, our region, our state and our country is a virus that is taking over," Ms Breed said, announcing the new clampdown.
"We are on pace to run out of hospital beds to care for patients the day after Christmas. We must turn this around now."
San Francisco's Health Order is expected to be in effect through 4 January 2021.
California Governor Gavin Newsom, also a Democrat, said on Thursday he would impose similar stay-at-home orders statewide, to take effect region-by-region as intensive care beds reach capacity.
Ms Breed said she was unwilling to wait for Mr Newsom's mandate to take effect in San Francisco, adding: "If you're not working to stay ahead of this virus you're falling far, far behind and very quickly."
Starting at 10pm this Sunday, San Francisco will close all outdoor dining, outdoor playgrounds, zoos and aquariums along with other measures, according to a statement on the mayor's website.
"Low contact retail such as pet grooming, electronics or shoe repair services, may only operate in a curbside drop-off context," the statement read. "All other retail, including grocery stores must reduce capacity to 20%."
Both Mr Newsom and Ms Breed have been criticised after dining on separate nights in November at the same upmarket Napa County restaurant, the French Laundry, despite repeatedly admonishing Californians to avoid such outings.
More than 213,830 new cases and 2,861 deaths were reported in the US on Thursday, according to a Reuters tally of official data. Figures for the past 24 hours are not yet known.
Some experts project the death toll could soon surpass 3,000 per day.
The spiralling pandemic has prompted state and national political leaders to order increasingly aggressive countermeasures while Americans wait for governmental approval of vaccines developed by drug companies Pfizer Inc and Moderna.
