The new case number means the county has seen a record-high number of new COVID-19 cases for the fourth time in the past five days.
The new daily number breaks the previous record of 8,860 set Friday.
The county is also reporting another 44 deaths, and the number of people hospitalized due to the virus has risen again, reaching 2,769, the highest level of the entire pandemic. It is also the fifth straight day COVID-19 hospitalizations surpassed an all-time high.
RELATED: Stay-at-home order to take effect in Southern California on Sunday, triggered by ICU capacity's drop below 15%
Of those hospitalized, 23% are in the intensive-care unit, according to the L.A. County Public Health Department.
"This week, almost 49,000 people tested positive for COVID-19. We can anticipate based on our experience, that 10% of newly infected individuals are likely to require hospital care a couple of weeks from now," county Public Health Director Barbara Ferrer said. "That translates to close to 5,000 patients, and if even 20% of these patients need care in the ICU, they will require 1,000 staffed ICU beds. This is our likely reality in 2 weeks."
"And if we all can't get behind the existing directives to stay home as much as possible and avoid all non-essential activities and places where you are likely to be in contact with non-household members, we are likely to bear witness to one of the worst healthcare crises our county has seen in our lifetime," Ferrer added.
Amid a surge in coronavirus cases, California's new health order went into effect on Saturday afternoon, and a stay-at-home order in Southern California was officially triggered by a drop in ICU capacity at the region's hospitals. Regions have 24 hours to implement the rules, which stay in effect at least three weeks.
L.A. County announced it will modify its health order to align with the state's regional stay-at-home order to "prevent crowding and mingling among non-household members and overwhelming our healthcare system."
1/ SoCal ICU capacity is below 15%. Effective Sunday night at 11:59pm, the LA County Health Officer Order will align with the State Regional Stay Home Order to further prevent crowding & mingling among non-household members & overwhelming our healthcare system. pic.twitter.com/otUCAjZZ7A— LA Public Health (@lapublichealth) December 5, 2020
"Because L.A. County is in the Southern California Region, the Los Angeles County Health Officer Order will be modified to fully align with additional safety measures across sectors and the required effective date," the county public health department stated. "The Order prohibits private gatherings of any size, closes sector operations, and requires 100% masking and physical distancing. The State Regional Stay at Home Order is similar to the existing County Safer at Home Health Offer with additional sector closings."
When a region has fewer than 15% of its ICU beds available, new restrictions are imposed. The California Department of Public Health said Southern California's ICU capacity was 12.5% on Saturday.
The state-mandated "regional stay-at-home" order goes into effect at 11:59 p.m. Sunday for Southern California.
For more information on the types of businesses impacted by the state's regional stay-at-home order, click here.