How the coronavirus flooded California and swamped L.A.

It started in Orange County a little more than a year ago.

With the sun long set and many residents in bed, the public health department posted a message on Twitter at 11:08 p.m. last Jan. 25. A traveler from Wuhan, China had tested positive for the novel coronavirus.

Twelve hours later in Los Angeles, Barbara Ferrer, the top public health official in America's most populous county, had an announcement. A second person returning from Wuhan had been hospitalized with the virus.

At the time, there were only four known cases in the United States. Some leaders, including the president, gave assurances that the virus would soon be snuffed out.

They were wrong. There have been 26 million confirmed cases and more than 400,000 deaths nationwide. In California, more than 3 million people have tested positive and 40,000 have died.

The Times has been tracking the numbers since the pandemic’s earliest days. A look back on the first anniversary of the outbreak shows how the spread across the state unfolded in four distinct chapters, leading to a massive winter swell which the state is still recovering from.

An outbreak in the Bay Area spreads south

The virus made its first footholds in the San Francisco Bay Area, where several cruise ships carrying infected passengers were quarantined at sea.

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Hopes that the virus could be contained aboard the ships were soon dashed. It began spreading in Bay Area communities in late Februrary, leading to the highest infection rates in the state.

California’s five regions





Bay Area

San Joaquin




In early March, the first coronavirus-related death was reported in Placer County. Gov. Gavin Newsom declared a state of emergency. With cases piling up in Silicon Valley, Santa Clara County officials banned mass gatherings.

Talk began of “social distancing” in Los Angeles but the L.A. Marathon went on as planned on March 8. At the time, there were 14 known cases in the county.

As infections continued to spread, leaders began to take more decisive action. On March 19, Newsom ordered all Californians to stay home. It wouldn't be enough.

At that time, there were 1,200 cases statewide. Four days later, cases had doubled. Two weeks later, on April 1, they had quadrupled and Southern California had shot past the Bay Area to establish itself as the new epicenter in the state.

Tracking the coronavirus outbreak

Follow the latest data on the spread of COVID-19 in California with our coronavirus tracker.

A summer surge ravages agricultural areas

Beginning in May, cases per person skyrocketed in the rural farming communities of San Joaquin Valley and along the border in Imperial County.

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Hard hit were low-income essential workers, many of them working in the fields and living in crowded housing.

By July, Imperial County’s two hospitals were overwhelmed. Hundreds of patients had to be transported elsewhere for treatment. To date, one out of every seven residents in the county has tested positive. More than 500 have died.

The spread in the state’s Central Valley wasn’t limited to the fields. Outbreaks were reported at state prisons all across the state.

Before the end of July, the virus had spread to California’s most remote reaches. That’s when the first cases were reported in Modoc County, near the Oregon border. All 58 of the state’s counties had recorded a case of the coronavirus.

By August, the coronavirus had spread to all 58 counties

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58 counties

As the summer surge faded, Newsom introduced a color-coded system that allowed some counties to begin reopening in September and October.

Cases triple as the virus overwhelms the state

The reprieve was short-lived. The last weeks of October saw a slight uptick in cases across the state, soon followed by an unprecedented surge.

Experts say pandemic fatigue and a sense that the threat was over played a role. At Thanksgiving, a record number of people traveled for the first time since the spring. It was soon clear an influx of new coronavirus patients would create a crisis in California’s hospitals.

The virus surged in cities, prisons and some of the most isolated communities.

On Nov. 13, 292 days after that late night press release was issued by Orange County officials, the state surpassed 1 million coronavirus cases.

State officials announced a curfew. Thirty-one counties saw record highs in new daily cases before Thanksgiving. A new region-based stay-at-home order went into effect. Then on Christmas Eve, the state hit 2 million total cases, doubling in just 41 days.

Just 30 days later, the state surpassed three million total cases. At least one out of 13 Californians had tested positive.

Case rates spiked dramatically in the winter months

Cases per 100k
712,268 cases

Vaccines arrive as the surge subsides

In late December, hope emerged. The first COVID-19 vaccinations were rolled out to healthcare workers and nursing home residents. Daily case counts began to drop in January.

The state’s vaccination campaign has been shaky at best, marked by missed goals, limited supply and data reporting problems.

Still, vaccination centers have opened up across the state, including mass distribution sites at Dodger Stadium and Disneyland. On Jan. 25, the remaining stay at home orders were lifted.

One year after the crisis began, Southern California — particularly Los Angeles — again has the highest concentration of cases. To date, one in every nine residents of L.A. County has tested positive.

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Experts warn that there still remains a possibility for another surge.

A mutant, more contagious variant of the virus is rapidly spreading across the U.S., and officials are voicing worries about Super Bowl parties and reckless gatherings at outdoor restaurants.

Times staff writer Rong-Gong Lin II contributed to this story. Ryan Menezes and Ryan Murphy provided additional programming.