In the heart of Flatbush, Brooklyn, past the bright Haitian takeout corner spot, with its aroma of richly fried pork, and down the block from La Difference driving school, an anxious crowd packed the front waiting room of the district office for Councilman Mathieu Eugene.

Older residents of Brooklyn and recent immigrants from Haiti all wanted to know: What now?

On Monday night, the Department of Homeland Security announced that it would — in 18 months — end a program known as Temporary Protected Status for Haitians affected by the deadly earthquake that rocked the island in 2010.

T.P.S., as it is known, allows people from countries crippled by natural disasters or armed conflicts to live and work legally in the United States. By its nature, T.P.S. is supposed to end at some point, but under previous administrations its protections had been extended for years or even decades. The status of T.P.S. permit holders from Honduras and El Salvador has not yet been decided, but Homeland Security deemed Haiti ready to accept its citizens, and gave Haitians living in the U.S. until July 2019 to prepare.

“I went to Haiti last year and I can tell you, it’s not ready,” Peddy Jean-Louis, 50, said while waiting for an appointment to check on his status. “It is still damaged.”

With a T.P.S. work permit, Mr. Jean-Louis has a job as a cook. He hoped his daughter, an American citizen, would be able to sponsor him for a green card. “I am lucky, I have an option.”

The others chatting somberly in French and Creole beside him were not as hopeful. But they brightened briefly when their Haitian-born City Council member, Dr. Eugene, burst through the storefront door and started shaking hands.

A few minutes later, in his back conference room, Dr. Eugene, a Democrat who has been on the Council since 2007, confided that he, too, was worried.

“These 18 months are going to be 18 months of panic, of stress, and that will create a mental situation,” Dr. Eugene, who trained as a medical doctor, said. “This is going to create another disaster. We are going to break families apart.”

Dr. Eugene also said the 18 months gave advocates more time to organize, perhaps for a more permanent status. “If they are still here, we are going to continue to fight,” he said.

There are approximately 5,200 Haitians living with T.P.S. in the city, according to the New York Immigration Coalition, an advocacy organization, and about 59,000 living in the United States since the earthquake. For some Haitians who had entered the country illegally or overstayed visas, T.P.S. allowed them an opportunity to live and work openly.

Kane André, a naturalized citizen from Haiti who is a church minister and a real estate agent, was looking on the bright side. “We were happy to have the permit extended,” he said. “What I see is that if they plan to have more jobs, that would be good for the country. We fought here to get a better Haiti and so it will be easier to go back.”

But, still, community leaders and those in small businesses wondered if such an eventual departure would have a ripple effect on Flatbush, if not the wider New York economy.

In the back room of La Difference Auto School on Rogers Avenue, the walls of a Haitian cultural center were adorned with a large map of the country, paintings and posters in Creole.

The manager of the driving school, Ernst Severe, feared the empty room would be a sign of things to come. Immigrants from Haiti who had gotten T.P.S. after the earthquake represented about a third of his clients. “I think it’s going to affect my business greatly,” Mr. Severe, 61, said before starting a driving lesson.

At a money transfer station located in a nearby barbershop, Manoucheka Ostane, 35, said a good portion of the business comes from remittances immigrants send back to their families in Haiti.

“If you don’t send anything, you’re not going to get anything,” she said, referring to a commission. “If there’s nobody coming in, we’re going to have to close and look for something else to do.”

As much as Haiti’s still-struggling infrastructure dominated conversation in Brooklyn, Joenald Pierre wondered who was left on the island to welcome the earthquake refugees. An American citizen born to Haitian parents in New York, he was personally devastated by the disaster.

“Where do you go?” said Mr. Pierre, 44, while eating griot, a Haitian pork dish, at Bebe Fritay. “Where do you go? I lost half my family in the earthquake. Twenty cousins died.”

Zachary Laresche, 52, opened Casa 1 Tire Repair in Flatbush in 2013, after he got a T.P.S. permit.

“It’s not easy for a businessman like me to go back,” he said, explaining that the island’s economy would not support a small business. He figured that many people would defy orders of deportation to stay in the United States.

But Mr. Laresche said he would decide his future when the time came.

“I’m a citizen of the world,” he said.

On Tuesday, Dr. Eugene met in his office with a Haitian-Canadian member of Parliament, Emmanuel Dubourg. Dr. Eugene visited Montreal several months ago and was shocked to see the thousands of Haitians who had migrated there, supported by family, but with a tenuous hope for legal status.

The two men wanted to dissuade Haitians from illegally crossing into Canada.

“The message remains the same: It’s not a free ticket to come to Canada,” Mr. Dubourg said in an interview. Since the summer, he has been serving on a government task force addressing illegal immigration. According to Immigration, Refugees and Citizenship Canada, a government agency, from January to September 6,360 Haitians applied for asylum, but only 10 percent received it.

For those who don’t have a valid asylum claim, Canada will send them back to their country of origin, Mr. Dubourg said.

“We welcome them with dignity,” he said. But “it doesn’t mean that they are going to get permanent residence in Canada.”