Mayor London Breed matched that outlook, saying if you're not staying ahead of the virus, you're falling far behind, very quickly.
To curb the spread, San Francisco is joining several other Bay Area jurisdictions in implementing a stay-at-home order ahead of state action.
RELATED: Here's what will close under a stay-at-home order in the Bay Area
Unlike Gov. Gavin Newsom's plan announced Thursday, the Bay Area's regional stay-at-home order will take effect this Sunday, lasting through Jan. 6.
San Francisco, along with other Bay Area counties, is opting in to the Governor's regional Stay at Home Order effective Sunday at 10pm.— London Breed (@LondonBreed) December 4, 2020
We're on pace to run out of hospital beds to care for patients the day after Christmas. We must turn this around now. https://t.co/F0qwFnCb9e
Breed was clear in her message Friday, what San Francisco is going through is difficult, but "there is a light at the end of the tunnel."
WATCH: Mayor Breed says what San Francisco is going through is difficult, but 'there is a light at the end of the tunnel'
Hospitalization and cases are rising in San Francisco, and Dr. Colfax said those numbers are likely to worsen in the coming days and weeks.
The city is averaging 140 new cases per day, compared to just 34 per day in October.
"We were in a much better place back then," Breed said.
Colfax said the city has about one week to stabilize the number of COVID-19 patients in the city's hospital system.
#BREAKING Starting Sunday Dec 6 these activities are required to suspend operations in San Francisco per @LondonBreed: hair and nail salons, barbershops/tattoos/estheticians, outdoor dining, outdoor museums, playgrounds— Kate Larsen (@KateABC7) December 4, 2020
"Our biggest fear all along is that we won't have a bed for you or your mother or your grandmother or grandfather when they get sick," Breed said. "(It's) the reality we'll be facing unless we slow the spread. The measures we've tried so far simply haven't bent the curve the way we need it to."
RELATED: 5 Bay Area counties to announce new restrictions, sources say
Under the Bay Area stay-at-home order, restaurants will be limited to takeout and delivery, personal services like nail salons and hair salons will close and retail store capacity will be capped at 20%.
If the virus continues at the current rate, Dr. Colfax believes San Francisco hospitals will have a shortage of ICU beds by Dec. 26.
"If this trend continues, and we do not slow the spread of the virus, we will be unable to care for people in San Francisco's hospitals, and it's not only because of beds, but it's because we will not have enough nurses and doctors to adequately care for people," Colfax warned.
Colfax said 75% of hospital beds in California are currently filled.
"There will be no place to transfer patients. There will be no other place from which to hire more nurses or doctors, which we would otherwise be able to do in a localized health crisis," Colfax warned.
He emphasized this is why the city is taking such "aggressive action."
"This time it will be tough, but the alternative is unthinkable," Colfax said.
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