Lisa Cohen stood in a retired trolley tunnel about 20 feet beneath Dupont Circle, talking determinedly into a microphone that didn’t work.

Cohen — formerly Lisa “Too Fierce” Foster, a District-born International Female Boxing Association junior champion — came to the Dupont Underground art gallery Saturday to talk about her life and career. She shared the space with a photo exhibition, a Czech DJ and a “wine walk.”

“I love this space. What’s not to like?” said Cohen, 52, holding her championship belt. “I know this city. It feels like home. This is D.C. This is what it used to be.”

The scene, in which hundreds of people with different interests mingle in trolley tunnels reclaimed decades after they were abandoned, might not be sustainable. One day after Cohen’s talk, Dupont Underground missed a $150,000 rent payment to the city. With its lease running out in April, its future is uncertain.

Gallery administrators say they are reluctant to hand over the money without assurances from the city that they can stay. Those behind the nonprofit say they are close to their goal of creating an art hub but need the city as a partner — and, at least until recently, the city has been mostly silent.

Laura London, a co-chair of Dupont Underground, said the group repeatedly reached out to the city’s Office of the Deputy Mayor for Planning and Economic Development this year but received no meaningful response. The city agency, which will meet with Dupont Underground this week, said Friday that it is willing to let the 75,000-square-foot space stay open for now.

Dupont Underground administrators hope the meeting eventually yields at least a 10-year lease. But what happens after Sunday’s missed rent payment and April’s lease expiration isn’t clear.

“No one wants to see the space go vacant,” London said. “That is a worse-case scenario for both the city and the neighborhood and us. . . . The fact that they have not worked with us makes that a realistic possibility.”

In a statement, the Office of the Deputy Mayor for Planning and Economic Development said the property is “a unique space with broad potential for a number of arts, cultural and entertainment uses.”

“Although Dupont Underground has signaled it will not be able to fulfill the terms of its agreement with the District of Columbia, we will discuss ways that they can continue to keep the space activated for an interim period,” the statement said. “The time will allow Dupont Underground to demonstrate they can become financially viable to make capital improvements and realize the full potential of the space. We remain committed to keeping this unique space as an asset of the creative economy.”

City officials did not comment on possible changes at the venue after Dupont Underground’s lease expires.

In a letter Thursday to interim deputy mayor for planning and economic development John Falcicchio, D.C. Council Chairman Phil Mendelson (D) and D.C. Council member Jack Evans (D-Ward 2) said they supported the organization’s request for a ­10-year lease and said the $150,000 rent payment should be waived “given the dismal history of utilizing the tunnels prior to Dupont Underground.”

“We see this as a good investment for District residents, the Dupont Circle neighborhood, and the District’s arts community,” the letter said.

The game of bureaucratic chicken over Dupont Underground’s fate comes near the end of a five-year agreement decades in the making.

The streetcar tunnels were closed in 1962 and sat idle before their reinvention as a food court in the 1990s. That project failed in 1996 after its developer was sued by tenants for breach of contract. The lights were turned off again until 2014, when D.C. architect Julian Hunt won a years-long battle to persuade the city to turn the tunnels over to artists.

Hunt, who worked as an architect in Barcelona before moving to the District — and was inspired by the European city’s grand public spaces — saw the tunnels as “something that could have great utility and use for civic life,” he said. The dream butted against D.C. bureaucracy, as Hunt recalled that a permit for a launch party was denied because the tunnels weren’t registered with the Department of Consumer and Regulatory Affairs.

“It was very difficult to move conventional thinking,” he said. “I thought what we were doing was a civic exercise in . . . helping the city speak to its soul.”

The District and Dupont Underground agreed to a five-year lease for $150,000 due this past Sunday — an amount the organization said it had raised in 2017 but, given its current finances, is not forthcoming.

Hunt said paying rent is “totally unfair” given the civic duty the organization performs.

“We’re not developers,” he said. “To me, it was a failure of imagination — a failure of sympathy.”

Dupont Underground CEO Robert Meins said the gallery, with four part-time employees and 21,000 visitors annually, is profitable, funded mostly by income earned while renting out the space. The nonprofit also received a grant from the D.C. Commission on the Arts and Humanities.

Meins, however, said the space needs about $60,000 worth of infrastructure improvements, including a sprinkler system, on top of the late $150,000 rent payment to keep its certificate of occupancy. The organization is hesitant to pay the city when it could be evicted in months and has already canceled a program planned for 2020 with the Austrian Embassy because of its existential uncertainty.

“We’re not going to do a $60,000 investment for a month-and-a-half worth of programming,” he said. The space, which isn’t heated, closes during the winter months.

Meanwhile, Dupont Underground has identified at least one partner possibly willing to pay for long-term use of the space if the organization and the city can reach a longer-term agreement.

Lars Boering, managing director of the World Press Photo Foundation, a nonprofit that showcases international photojournalism, said Dupont Underground is “a gap that we can step into.” The foundation has previously shown the work of its contest winners at the venue and would like a permanent home in the District, especially after the closure of the Newseum.

Boering compared the gallery to World Press Photo’s Amsterdam headquarters, which is on the grounds of a former gas plant. He said it would be a great place to “have a long-term relationship with.”

“It’s hard to find a space that matches the possibilities and look and feel and soul that Dupont Underground has,” Boering said. “It’s great as it is right now. . . . I like the roughness of it.”

Some residents say the reimagined art space has been a positive addition for the neighborhood.

Tim Touchette, chairman of Historic Dupont Circle Main Streets, said the area needs more “experiential events” to make it a bigger destination, adding that Dupont Underground is a unique attraction.

“You’re not going to find an underground event space quite like that anywhere in D.C.,” he said. “The city should make use of an asset. If people are willing to pay, it helps the city, brings jobs, and brings tourists and locals out of their homes.”

Because only half of the tunnel system has been reclaimed, Meins said he sees more potential in Dupont’s underground than Dupont Underground. Carrying a lamp, he walked through a set of dank, abandoned tunnels — a “Walking Dead”-like warren once occupied by the homeless and where a deserted food court with a Clinton-era “Pizza Express” sign still hangs.

Meins wants it all for art, but the city has to give it to him.

“Nothing else works down here,” he said. “We need a game-changer.”