NEW YORK — In the hours before opening night on March 12, 2020, "Six" seemed poised to be a big Broadway hit. Kevin McCollum, one of the musical's lead producers, had booked Tao Downtown, a chic Asian fusion restaurant in Chelsea, for the after-party. Friends of the cast and creative team flew in from all over the world.

The $12 million in advance ticket sales, and strong word of mouth from earlier London and Chicago performances, as New York-based critics prepared to weigh in, bolstered a sense of buoyant expectation. “The opening night gifts for the cast were lined up, people were coming to pick up their tickets all morning,” McCollum recalled. The traditional red carpet was set up outside the Brooks Atkinson Theatre on West 47th Street in anticipation of the 6:30 p.m. performance.

And then, just like that, the lights went dark on a potential smash.

The most exciting day on the “Six” calendar — through no fault of its own — turned out to be its most devastating. The very day that “Six” — a glossy multiracial, pop-musical take on the six wives of King Henry VIII — was supposed to open, was also the day that Broadway closed.

The coronavirus has wreaked havoc with so many lives and livelihoods over the past 12 months that it would be foolhardy to suggest the shuttering of a musical is anything but a single bad ripple in a tidal wave of misfortune. But for the dozens of Broadway workers who were counting on “Six” — the stagehands, actors, publicists, ushers, janitors, musicians, writers and producers — the show’s shutdown was a poignant letdown. And, though they didn’t know it at the time, it was just the beginning of a long period of idleness and uncertainty.

“It was like a real whiplash of a moment,” said Adrianna Hicks, one of the musical’s six leads, who plays wife number one — Catherine of Aragon. When word reached her in the afternoon that the show wouldn’t go on, a thousand thoughts leaped into her head: getting her mother back on a plane to Texas; getting groceries in case she couldn’t later; getting her personal items out of her dressing room. “Because you’re like, ‘I don’t know how long it’s going to be,’ ” she explained. “We just hit a brick wall.”

For Abby Mueller, who plays wife number three, Jane Seymour, the news was not so much a shock as a sad confirmation. “With what was happening in the world, it just felt like, okay, yeah, I get it. The timing is, you know, disappointing. But what are you going to do? And what do you have control over?”

The timing, indeed, was roundly disappointing. Days before, I had attended a preview performance of “Six” and had just filed my own assessment of the show, which would have posted online as the curtain came down that night. But because the opening was canceled, no reviews appeared. My rhapsodic endorsement (I now feel free to reveal) exists out there in the ether somewhere, a floating virtual fragment of a Broadway hit that almost was.

The romance of Broadway is so eternally tied to the outcomes of opening nights that the story of “Six” is likely to be retold for years to come. Although strikes have caused some short interruptions over the decades, the theater industry has never known a protracted period of nonperformance such as this: Even during the 1918 flu pandemic, Broadway theaters remained open. After 9/11, Broadway took two days off and was back, on Sept. 13, 2001.

McCollum remembers the pressure he felt on the afternoon of March 12, as Broadway producers held an emergency meeting. The state of New York was on the verge of shutting Broadway and other public spaces, and all eyes turned to McCollum. What went through his mind, he recalled, was: “I do not want to be the last show on Broadway to open right before it shutters. I want to be the first show to reopen.”

“Six,” with a book and score by Toby Marlow and Lucy Moss, was set to open during one of what McCollum calls Broadway’s “harvest seasons”: the times of the year that producers deem most conducive to sales. March ushers in the annual spring traffic jam on Broadway, when the calendar is crowded with openings for shows trying to beat the deadline for the season’s all-important Tony nominations, usually around May 1.

The 80-minute show had started as a project by Marlow and Moss, students at Britain’s Cambridge University, that premiered successfully in 2017 at the Edinburgh Fringe, with Moss and Jamie Armitage directing. “It all got a bit wild and people came to see it,” Marlow said in a Zoom interview from London with Moss and Armitage. “And then eventually Kenny Wax [a London producer] was like, ‘I’ve got another theater in London where there’s a couple of Mondays over Christmas where there’s nothing on. Do you want to do some showcases?’ And we’re like, ‘Yeah.’ ”

The next steps unfolded out of the manual for how an appealing theater entertainment gains momentum: a cast album, a U.K. tour, a run in London’s West End, a groundswell of social media popularity. Then interest intensified overseas, with a tour to Australia, and with a New York producer, McCollum — one of the original producers of “Rent” — coming aboard with Wax.

“As soon as they opened at the Arts,” I went and I said, ‘I’m in,’ ” McCollum recalled, of the musical’s run at London’s Arts Theatre in 2019. A well-received production at Chicago Shakespeare Theatre with a North American cast followed in May that year, and after stops in Boston, Edmonton, Alberta; and St. Paul, Minn., “Six” landed for four weeks of previews at the Atkinson in early 2020.

The arrival of “Six” was a turning point for Marlow, Moss and Armitage, all of whom would be making their debuts as Broadway artists. It would be the same for Paul Perez, the Atkinson’s house manager, who supervises all of the so-called front-of-house operations for the theater’s landlord, the Nederlander Organization. He’d arrived at the Atkinson in the midst of the long run of the previous tenant, “Waitress,” the musical. “Six,” in a sense, was to be his opening-night baptism by fire.

“It wasn’t just another show that I was opening,” he explained via Zoom from his native Southern California, to which he moved back during the pandemic. “It was that it would have been my first.”

“Six” was in previews as cases of the coronavirus popped up here and there, and the company began to take precautions, like curtailing stage door autographs, issuing gloves to the ushers and wiping down seats between performances. “Remember,” McCollum said, “we thought it was a surface virus.” An usher who had worked the show was subsequently diagnosed with the coronavirus, and as opening night approached, the news got graver.

“It felt like a horror film,” Armitage said. “You know, that thing, and it’s coming closer.”

Talking to the people involved in the production, one is reminded again and again how much remained unknown in the early days. Moss recalled that even as a shutdown became increasingly certain, the alarm about a potential long-term hiatus did not sink in. “Even when we heard that it was a shutdown, they were like, ‘We’ll be back in a month,’ ” she said. “Obviously, they were just trying to be optimistic. But literally, none of us had any idea.”

McCollum had been so optimistic earlier that week that he’d bought “six figures worth of sushi” for the party at Tao. And then, he recalled, on March 11 came the announcement that the NBA would be suspending games the next day. That made the urgency real.

Sometime around the March 12 midday meeting of producers and theater owners in the offices of their trade group, the Broadway League, McCollum learned that New York Gov. Andrew M. Cuomo (D) would be announcing the immediate shutdown of Broadway at 6:30 p.m., the exact early-curtain time for opening “Six.” “I said, okay, but I’ve got to get to the governor right now. I said [the announcement] has to be 5 p.m. I have paparazzi [invited] and people right now are getting dressed and putting on makeup to show up for the red carpet. And they have to know: ‘Don’t come.’ ”

Because “Six” missed its own party, McCollum hastily arranged a cocktail gathering at a spot that day near the theater for a farewell — an event that no one could have predicted would be the last time they’d be together for more than a year. It’s been a painful absence for everyone: Several of the “Six” actresses, collectively known as “the Queens,” declined to comment for this article, because the memories remain so raw. But Mueller and Hicks said they hold out hope for a return.

The marquee is still up at the Atkinson. The set is still onstage. The costumes are hanging on racks.

“We just know that ‘Six’ is so special,” Mueller said. “I’ve just retained this feeling, well, it’s going to come back. I would love to be a part of it.”

“Abby said it beautifully,” Hicks added. “It is just living day by day, hoping that this wonderful show will have another chance to shine on Broadway.”

That is the plan, McCollum concurs. With or without the sushi.