About two hours after Century 21 reopened as Century 21 NYC in Lower Manhattan on Tuesday, the store’s point-of-sale system crashed.

“This goes to show you that they should have never went out of business,” said Denise Danny, 58, from Staten Island. Ms. Danny, who had a shopping cart full of clothes, was standing in a line that had formed at a register on the department store’s second floor. “If it’s this crowded on the first day of the grand opening, you know the people missed Century 21.”

It was less than three years ago when the retailer, which was beloved for offering designer labels at a discount, declared bankruptcy and closed all of its stores, disappearing from the city’s shopping map like other fabled department stores including Abraham & Straus and Barneys.

At the time, Century 21 had 13 locations in four states. But arguably, none was as popular as its flagship location on Cortlandt Street in the Financial District, which was opened in 1961 by two cousins, Al Gindi and Samuel Gindi, who was known as Sonny.

After closing in September 2020, the flagship store sat empty because the company, which was then run by the second-generation owners Raymond, IG, Isaac and Eddie Gindi, still had a long-term lease on the space. Later in 2020, the Gindis bought Century 21’s intellectual property in a bankruptcy sale with hopes of eventually reviving the business, said Teresa Rodriguez, the vice president of marketing at Century 21 NYC.

Longtime customers may find the new Cortlandt Street store, which occupies four floors, more intimate than its predecessor, which took up seven. They will also notice that with the new name has come a new logo. The store’s inventory has changed slightly, too: It now includes vintage bags sourced by Two Authenticators, a company that finds and authenticates previously owned luxury goods that are sold through retailers like Century 21 NYC.

Before the store opened to the public on Tuesday morning, Mayor Eric Adams gave a speech and made the first purchase of the day: a blue Eton dress shirt for $129.99, more than half off its list price of $275.

By the time the first customers entered at about 11:30, a line had formed around the entire building. “I’ve been waiting for this day to come, because I’m a Century shopper, and I’ve been a Century shopper for many years,” said Gina Strachan, 83, from Brooklyn. (Ms. Strachan, like other longtime customers, referred to the store using a shortened version of its name.)

The first floor, which offers fragrances, sunglasses, bags and other accessories, filled up quickly. Many shoppers gravitated toward the center of the floor, where sales associates armed with keys stood by locked display cases full of Louis Vuitton, Saint Laurent and Gucci purses.

By 12:30, lines at the registers had grown longer, and the escalators were crowded. Early arrivals were already on their way out, and some, including Jamz Putra, were empty-handed. Mr. Putra, 27, from Manhattan, had come in search of Balenciaga and Vetements items, with hopes of reselling them for a profit. “I missed this place,” Mr. Putra said, adding that even though he hadn’t found anything that he could resell, he planned to return.

When the point-of-sale system went down that afternoon around 1:30, confusion erupted as lines got even longer and employees asked people to wait patiently. Security guards closed the store to new customers, and lines started to form outside again. Employees took advantage of the lull, restocking empty racks and rearranging displays that had been knocked over.

By 2:30, the cash registers were fully operational, and shoppers were shuffling in again. On the basement floor, which offers shoes, children’s clothes and luggage, a man and a woman piled their purchases into a suitcase before pushing toward the crowded escalators, explaining that they had a plane to catch.

On the first floor, Vladimir Dzuro, 61, from Manhattan, stopped to pose on a small red carpet that had been set up as a place for people to take photos. As another customer snapped his picture, the two had a brief chat about how excited they were that the store had reopened before they headed their separate ways to shop.

Mr. Dzuro said that he and his wife, who are planning to move to the Czech Republic in October after 15 years of living in New York, were happy to be able to shop at Century 21 again before they left the city. He added that they had family members visiting in June and intended to bring them to the store.

While perusing the perfume selection, Anna Evans said her fondness for Century 21 was not only because of its deals. Ms. Evans, 37, from Manhattan, said the store had been a large part of her childhood.

“It’s so nostalgic to me,” she said. “I’ve been waiting for years for the reopening.”

After a bit of browsing, Ms. Evans said that her impression was that the new store was “not as good” as it had been in the past. But, she added, “I just walked in, so I need some more time.”