Curtains are rising again after the Omicron surge caused widespread cancellations, but attendance has fallen steeply. Nine shows are closing, at least temporarily.The reopening of Broadway last summer, following the longest shutdown in history, provided a jolt of energy to a city ready for a rebound: Bruce Springsteen and block parties, eager audiences and enthusiastic actors.But the Omicron variant that has barreled into the city, sending coronavirus case counts soaring, is now battering Broadway, leaving the industry facing an unexpected and enormous setback on its road back from the pandemic.In December, so many theater workers tested positive for the coronavirus that, on some nights, half of all shows were canceled — in a few troublesome instances after audiences were already in their seats.Now, producers have figured out how to keep shows running, thanks mainly to a small army of replacement workers filling in for infected colleagues. Heroic stories abound: When the two girls who alternate as the young lioness Nala in “The Lion King” were both out one night, a 10-year-old boy who usually plays the cub Simba went on in the role, saving the performance.Broadway shows have been using social media to remind potential ticket-buyers that performances are still happening. The revival of “Company” is among many using the hashtag #BroadwayIsOpen.An Rong Xu for The New York TimesBut there’s a new problem: Audiences are vanishing.During the week that ended Jan. 9, just 62 percent of seats were occupied. That’s the lowest attendance has been since a week in 2003 when musicians went on strike, and it’s a precipitous drop from the January before the pandemic, when 94 percent of seats were filled during the first week after the holidays.The casualty list is growing. Over the last month, nine shows have decided to close their doors, at least temporarily. “To Kill a Mockingbird,” a huge hit before the pandemic, announced last week that it would close until June; on Sunday “Ain’t Too Proud,” a successful jukebox musical about the Temptations, closed for good.Box-office grosses are falling off a cliff. The all-important Christmas and New Year’s weeks, which producers count on each year to fatten their coffers in anticipation of the lean weeks that follow, generated just $40 million this season, down from $99 million before the pandemic. Requests for ticket refunds are now so high that on some days some shows have negative wraps, meaning they are giving back more money than they are taking in.“This is the worst I have ever experienced,” said Jack Viertel, a longtime executive at Jujamcyn Theaters, which operates five Broadway houses.Over the long run, industry leaders say, there is every reason to remain bullish about Broadway. Until the pandemic, the industry had been enjoying a sustained boom, fueled by a rebound in the popularity of musicals and by New York’s gargantuan growth as a tourist destination. And this downturn might not last long: There is some evidence that the Omicron surge may be peaking, at least in some parts of the country, including New York.The musical “Ain’t Too Proud,” about the Temptations, was a hit before the pandemic, but decided to close after coronavirus cases forced the show to cancel multiple performances over the holidays. An Rong Xu for The New York TimesBut before it eases, the slump will cost investors tens of millions of dollars, and will push theater workers back into unemployment, as dwindling attendance forces productions without abundant reserves to close. And the distress is not just financial: Artists spend years developing shows before they get to Broadway, so a premature closing is a crushing blow.“It’s harrowing, and there will be a lot of damage done,” Mr. Viertel said. “Some shows will be put out of business permanently, and this will be career ending for some individuals.”Dominique Morisseau, the playwright who wrote the book for “Ain’t Too Proud,” and whose new play, “Skeleton Crew,” is now in previews following two virus-related delays, called this moment “extremely painful.” “My play is about plants shutting down during the auto industry collapse, and factory workers wondering every day, ‘Is it shutting down?’” she said. “Now that’s how we’re coming to work.”The Broadway League, which represents producers, has asked labor unions to consider pay cuts to help shows survive this rough patch. At one point, in a step previously reported by The Daily Beast, the League asked workers to accept half-pay when Covid-19 forced performance cancellations; there have also been discussions about offering lower pay for scaled-back performance calendars.“We’re doing everything we can to keep as many shows open as possible,” said Charlotte St. Martin, the president of the Broadway League, citing safety protocols and marketing efforts as well as labor discussions.The talks stalled as unions sought more financial information.A revival of “The Music Man” canceled multiple performances just days after starting previews when both of its stars tested positive for the coronavirus, but it is now up and running again.An Rong Xu for The New York Times“It’s fair to say that all the unions recognize that shows remaining open is important — that represents jobs for actors and stage managers and everyone else who makes a living in the live theater,” said Kate Shindle, the president of Actors’ Equity. But Ms. Shindle noted that Broadway shows had received tens of millions of dollars in federal aid last year, and that the industry is no longer even disclosing weekly box-office grosses for individual shows, as it did before the pandemic. “Pretty universally, the unions’ response has been that if you want us to make financial concessions, we need financial transparency,” she said.Meanwhile, shows are collapsing. There are always closings in January, a soft time of year for Broadway, but this season a crush of announcements started in December, usually one of the most lucrative months. The musicals “Ain’t Too Proud,” “Diana,” “Flying Over Sunset,” “Jagged Little Pill” and “Waitress,” as well as the play “Thoughts of a Colored Man,” all decided to close earlier than planned after Omicron hit. And three other shows, including “Mrs. Doubtfire” and “Girl From the North Country” as well as “Mockingbird,” said they would close for a few months and then attempt to reopen.“If it means that shows get to come back, hooray,” said Jenn Gambatese, the lead actress in “Mrs. Doubtfire.” “The alternative was, run another week and buh-bye.”More and more theaters are now dark. By next Sunday, there will be only 19 shows running in the 41 Broadway theaters. Cast and crew members from shuttered productions are trying to figure out whether they even worked enough weeks to qualify for unemployment; those who do will get less assistance than they did earlier in the pandemic, because the maximum weekly benefit in New York is now $504, down from $1,104 when the federal government was offering a supplement.This is a good time for bargain hunters: Discounts are available for many shows at the TKTS booth, and NYC & Company’s annual Broadway Week, which offers 2-for-1 tickets to most shows, has been extended to 27 days. An Rong Xu for The New York TimesThe surviving shows seem to have figured out how to avert the cancellations that bedeviled the industry last month.One reason: So many workers have already tested positive, and are now back at work (and, notably, no performers are known to have been hospitalized during this latest round). More important: Productions have trained and hired additional replacement workers, including for crew members.Playbills are regularly stuffed with cast-change inserts. One night, Keenan Scott II, the playwright of “Thoughts of a Colored Man,” kept his show afloat by going on to replace an actor who tested positive. “Come From Away” saved a performance by deploying eight swings, including alumni and a touring performer who had never worked on Broadway. At “Wicked,” a longtime understudy who had left Broadway to become a software engineer in Chicago returned and performed as Elphaba.The Coronavirus Pandemic: Key Things to KnowCard 1 of 4Omicron in retreat. More