SACRAMENTO, Calif. — It was a simple family get-together; a wedding gathering. About 30 people went out to dinner.

Half came down with the coronavirus.

Los Angeles Mayor Eric Garcetti told that anecdote Wednesday as California reversed its economic reopening for much of the state in the wake of a resurgent COVID-19 outbreak.

Gov. Gavin Newsom on Wednesday shut down bars, wineries, museums, movie theaters and inside-restaurant dining across most of the state for three weeks — enough time to determine whether those actions will once again slow the spread of infections.

For the two-week period that ended last Monday, California's confirmed coronavirus cases increased 45% to nearly a quarter-million and hospitalizations increased 52% to 5,077. About 500 more patients were sick enough for intensive care treatment, bringing the state total of people hospitalized in ICUs to 1,528.

For most people, the coronavirus causes mild or moderate symptoms, such as fever and cough that clear up in two to three weeks. For some, especially older adults and people with existing health problems, it can cause more severe illness, including pneumonia and death.

Newsom's order affects Los Angeles and 18 other counties where nearly three-quarters of the state's roughly 40 million people live. Most of Southern California is covered by the order but not San Diego, which is faring better.

"This will be the last straw for a lot of restaurants" that already reduced indoor seating to meet state reopening guidelines, said Jot Condi, who heads the California Restaurant Association.

At the Crepeville restaurant in Sacramento, owner Derar Zawaydeh cussed when informed of the new mandate for restaurants. He has a few tables outside but most are inside and will no longer be used. 

But if the new shutdown is needed to reduce the risk of infection, he said, "then we really don't have much of a choice."

Last week the state took the unprecedented step of ordering Imperial officials to come up with a new health order and on Wednesday the most restrictive plan in California was approved. It bars nonessential gatherings of any size, shopping in stores and indoor religious ceremonies. 

In the San Francisco Bay Area, more than 40 school principals are quarantined after they were exposed to the coronavirus during an in-person meeting last month to discuss reopening campuses. A person who attended the June 19 meeting of administrators with the Santa Clara Unified School District tested positive a few days after the event, officials said.

Newsom imposed the nation's first statewide stay-at-home order in March, earning praise from public health officials as virus cases stayed relatively low in the nation's most populous state for more than two months. But the order devastated the economy, forcing most businesses to close and prompting more than 6.7 million people to file for unemployment benefits.

As the spread of the virus slowed in May, Newsom moved quickly to begin allowing businesses to reopen across the state. Bars got the green light on June 12 and images quickly emerged of throngs of patrons packed tightly together, many not wearing masks as required by the state. 

For people planning gatherings of family and friends this Fourth of July weekend, Newsom urged them to reconsider. In Los Angeles County, Public Health Director Barbara Ferrer said many outbreaks were linked to parties and gatherings of family and friends. 

The county announced 35 new deaths and more than 2,000 new cases for the fourth day in a row. Nearly 2,000 people also were hospitalized — the largest number since early May.

Garcetti said the data weren't specific enough to say what percentage of the uptick was caused by bar or restaurant reopenings, beach mingling, family gatherings involving relatives who don't live together or even mass protests over the police killing of George Floyd in Minneapolis.

"I know we're exhausted. I know that we let down our guard. I know some us think that we're invincible," Garcetti said. "But this disease reminds us that we're not, and that we have to be vigilant."

California also released new guidance Wednesday mandating churches and places of worship discontinue singing, chanting or other similar activities and that people inside wear masks. Gym-goers also must wear them, even when exercising.

In the Southern California city of West Hollywood, sheriff's deputies will issue citations to people not wearing masks, officials announced Wednesday. First-time offenders could face $300 fines. 

Dr. Jeffrey Klausner, an epidemiology professor at the University of California, Los Angeles, said the new restrictions could be an "over response." He said the state should consider other strategies to keep young people away from older people, who are more at risk for the virus.

"It appears we're playing a game of whack-a-mole. Every time there is an increase in cases we have to take a step backwards," he said.

Newsom's order applies to 19 counties that have been on the state's watch list for increasing coronavirus cases for at least three consecutive days. Besides, Los Angeles, they include: Contra Costa, Fresno, Glenn, Imperial, Kern, Kings, Merced, Orange, Riverside, Sacramento, San Bernardino, San Joaquin, Santa Barbara, Santa Clara, Solano, Stanislaus, Tulare and Ventura.