Cause, the philanthropub, shortly after it opened in November 2012. (Jeffrey MacMillan/For Capital Business)

The final straw for Cause, the one that ultimately led to the restaurant’s closing, came this summer when the air conditioning system stopped working.

The establishment closed for six weeks. The general manager quit, as did most of the wait staff. Neighborhood regulars assumed the bar — which opened October 2012 with the promise that it would donate all profits to charity — had shuttered for good.

It hadn’t. But the damage had been done. There were tens of thousands of dollars in lost revenue, and $15,000 in unforeseen expenses.

“That was a huge blow,” co-founder Nick Vilelle said. “We never quite recovered from it.”

The restaurant, in the District’s Shaw neighborhood, closed its doors for good on Dec. 23, 14 months after it opened.

Vilelle said he and his co-founder, Raj Ratwani, were still calculating final numbers. But, he said, “we lost a lot of money. It was a significant amount.”

Business started off well enough. The community helped raise $23,000 for bar stools and tables on the crowdfunding site Indiegogo. Steven Colbert mentioned the restaurant on his television show, and there was a write-up in the New York Times. Area organizations and nonprofit groups booked happy hours and holiday parties. There were weeks early on when the restaurant turned a profit.

But even though Cause racked up $220,000 in sales during the first three months of last year, it posted a loss of $8,746 that quarter.

The restaurant also struggled to attract the steady stream of locals its owners had hoped for.

“It worked out that we were too reliant on the events business,” Vilelle said. “We struggled with getting that regular weekend crowd.”

Even the messaging, Vilelle said, worked against the “philanthropub.” All of the buzz around Cause’s opening had focused on its charitable mission and its off-beat business model. Few mentioned the food or the specialty cocktails, even though the former executive chef of the Queen Vic had been brought in to run the show.

“Looking back, we struggled to develop a reputation for ourselves,” said Vilelle, 34.

Vilelle has a lot of ideas about what else might have gone wrong. Maybe he and Ratwani should have talked less about the company’s do-good philosophy and more about its gourmet burgers. Maybe they arrived in the up-and-coming Shaw neighborhood at the wrong time. There are other questions, too: Could the location on 9th Street NW, between a bar and an Ethio­pian restaurant, have been better? Should they have set aside money for advertising?

“Maybe that’s another lesson learned, that we tried to be too bare-boned.” Vilelle said.

And then there was the spate of restaurant openings in D.C. Newcomers such as Le Diplomate and Ghibellina stole much of the publicity thunder in Northwest D.C this summer.

“There was so much buzz about what’s happening on 14th Street,” Vilelle said. “How do you rise above all that noise and get people to come in this direction? We just couldn’t do it.”

Not that they didn’t try, with their own blend of gimmicks and weekly events. The general manager brought in comedy groups on Mondays and deejays on the weekends. The chef added a number of alcohol-filled cereal concoctions to the menu. (One such item came with Honey Nut Cheerios, dark honey whiskey, honey and half-and-half.)

“There are always going to be people who will say, ‘Of course it’s not going to work. These guys have no idea what they’re doing,’ ” Vilelle said, “It’s frustrating, but I guess they were right in this case. We didn’t pull it off.”

Vilelle admits it was a lofty goal to turn a $100,000 profit that first year. Even the most successful restaurants generally post losses initially.

“Ultimately, we did this to see how much money we could make and give to charity,” Vilelle said.

He noted the restaurant donated a total of $10,000 to six local charities, including Martha’s Table and Higher Achievement.

Vilelle and Ratwani started Cause using $300,000 of their own savings. The majority of that money went toward the down payment for the $930,000 building, which the pair still own and plan to ultimately rent out to another business.

Neither of the founders took a salary at Cause. Both kept their day jobs: Vilelle in international development, and Ratwani as a research scientist for MedStar Health.

In the end, it was sometime in December when the pair decided their business just wasn’t viable. Sales had been bad in November and December — typically peak restaurant season.

“When we were losing money during the good months, we knew it was just going to get worse,” Vilelle said. “At some point we had to be okay with that.”

Still, he says, the charitable model isn’t necessarily doomed. Similar ventures have cropped up in Houston and Portland, and so far, Vilelle says they are doing well.

“I don’t want people to look at us and say, ‘Oh this business model can’t work,’” Vilelle said. “We made some mistakes. We’re going to be honest about what we did wrong, and maybe someone can do it better.”