According to the Department of Public Health, 20% of the 4,864 people hospitalized with COVID-19 countywide were in the ICU.
Meanwhile, the rollout of Pfizer's COVID-19 vaccine continued after it was received by nine pre-designated sites across the county. The initial allocation was being used to vaccinate frontline health care workers ahead of an expected second shipment of Pfizer's vaccine next week.
In a statement, the health department expressed hope that a second vaccine, manufactured by Moderna, soon will receive emergency use authorization by the Centers for Disease Control and Prevention.
Thursday's new data was released hours after California officials announced that the Southern California region's ICU capacity had dropped to 0%.
California also reported a staggering 52,000 new cases in a single day - equal to what the entire U.S. was averaging in mid-October - and a one-day record of 379 deaths. More than 16,000 people are in the hospital with the coronavirus across the state, more than triple the number a month ago.
ICU capacity drops to 0% in Southern California as state reports 379 new deaths, shattering record
L.A. County's new cases bring its total to 580,325. Since the start of the pandemic, 8,664 deaths have been reported in the county.
In light of such numbers, a coalition of labor unions is calling on county leaders to enact a monthlong shutdown that would include curfews and the temporary shuttering of non-essential businesses.
Proponents of the plan, and some county supervisors, say it would only work if workers and businesses are paid to offset the economic losses.
"What we're doing is just not working," said Kurt Peterson of Unite Here Local11. "So we need to follow the science, we need to look at places where they've been more successful. In doing so, those places are places that have locked down for a certain period of time in order to get the virus under control."
Hospitals across California have all but run out of intensive care beds for COVID-19 patients, ambulances are backing up outside emergency rooms, and tents for triaging the sick are going up as the nation's most populous state emerges as the latest epicenter of the U.S. outbreak.
The Associated Press contributed to this report.