On a spring day in 1977, members of a fringe Muslim group, armed with shotguns and swords, took 100 members of a Jewish organization in Washington hostage. The group then stormed a rival mosque, holding prayergoers at gunpoint. And two blocks from the White House, the militants shot their way into the District’s government building, killing a reporter and a security guard, and leaving Marion Barry, then a council member, bleeding from a gunshot wound to the chest.

Forty years after one of the District’s most terrifying days, survivors of the “Hanafi siege” gathered for the first time in decades Thursday night to recount the dramatic if largely forgotten episode in Washington history.

“It was an unbelievable time, but I guess so many other things have eclipsed it,” said Mark Tuohey, then an assistant U.S. attorney, who entered the District building with police during the 40-hour hostage situation that followed. “We shouldn’t forget, because . . . in Washington, it may just be a matter of time” before a reprise.

In the national capital, where law enforcement officers often talk about the next terrorist attack as a question of “when” and not “if,” survivors Thursday searched for lessons that still apply. With hate crimes surging across the nation, they said one lesson seemed especially timely: Pay attention to those who feel marginalized.

The leader of the Hanafi siege, Hamaas Abdul Khaalis, had been a victim four years earlier of one of the District’s most horrific crimes. An Indiana native who became an admired jazz musician and converted to Islam, Khaalis in 1973 had begun publishing letters critical of a leader in the Nation of Islam. Months after doing so, he returned to his Shepherd Park home to find seven members of his family murdered, including his 9-day-old grandson, drowned in a wash basin.

From left, former D.C. police chief Maurice Cullinane, former U.S. attorney Earl Silbert and former assistant U.S. attorney Mark Tuohey discuss the 40th anniversary of the Hanafi siege on March 9, 2016, in Washington. (Ricky Carioti/The Washington Post)

[March 11, 1977: Tiny Hanafi sect’s followers devoted, U.S.-born]

A group of Muslims from Philadelphia later were convicted of the killings. But for the next four years, hate festered in Khaalis, prosectors would later say. He grew unstable and isolated, stockpiling weapons in his 16th Street NW home and recruiting fellow followers of the Hanafi sect of Islam to carry out his plan for revenge.

“I think it’s symbolic of the problem we face today,” said Arrington L. Dixon, a former council member who spent the siege barricaded in his office down the hall from the gunmen.

“We need to have people who know how to talk to them, to understand the tensions and results,” Dixon said, speaking at a panel discussion in the D.C. Council chambers. “Those people needed to have some more attention after this, when they went through this and lost their family the way they did. . . . Sure it’s been 40 years, but there’s a lot we can take from this.”

But the Hanafi siege was also an event from another era, before Twitter, Facebook or 24-hour cable news.

It took place during a decade of hostage-taking, from the deadly attack on Israeli Olympians in Munich in 1972 to Americans held in the U.S. Embassy in Tehran from 1979 to 1981.

In those incidents, the terrorists used hostages as bargaining chips for some larger goal, and negotiators believed the longer a situation could be drawn out, the better the odds for minimizing casualties.

A photograph from an exhibition by the D.C. Council on the Hanafi attacks in Washington. (N/A/Courtesy of Council of the District of Columbia)

“You just keep talking. You keep waiting them out,” Maurice Cullinane, who was D.C. police chief at the time, said Thursday.

‘They said they were going to die’

At about 11 a.m. on the morning of March 9, 1977, the mayhem began at the headquarters of the Jewish community service organization B’nai B’rith International, near the intersection of 17th Street and Rhode Island Avenue NW.

Khaalis and other men with guns and machetes stormed the building threatening to “cut people’s heads off.”

[Hanafis threatened hostages with death ]

Inside, they corralled prisoners into a construction area and set up what they told hostages was an “execution room.”

A half-hour later, gunmen entered the Islamic Center on Embassy Row. They used string from venetian blinds and rope to tie up more than a dozen people, including visiting students.

Then, before 3 p.m., two men with shotguns exited a cab on Pennsylvania Avenue with a plan to take Mayor Walter E. Washington at gunpoint. On the fifth floor of the District’s government building, they made a wrong turn and settled for a dozen council staffers and lobbyists.

Security guard Mack Cantrell went to investigate, and as he opened a door to the council suite, he was shot in the head. Maurice Williams, a 24-year-old reporter, also was struck and killed, and a shotgun pellet ricocheted down the hall and struck Barry an inch from the heart.

[Barry a ‘very lucky’ man]

Soon Khaalis was talking to police and reporters. He blamed a “Jewish judge” for not doing more to convict conspirators in his family’s killing and demanded that the men who committed the murders be delivered to him.

Afraid of more attacks, police rushed judges out of D.C. courtrooms. Federal monuments were closed. At the White House, a planned gun salute to honor the visiting British prime minister was canceled for fear the hostage-takers would think they were under siege.

Ambassadors from Egypt and Iran, whose citizens were among the 149 hostages, became involved in negotiations. Before dawn on the third day, Khaalis accepted a deal to set everyone free. Prosecutors agreed that he, too, would be allowed to go home pending trial.

On March 12, 1977, the lead story in The Washington Post began: “For once, the news from Washington was joyous: a great city, our nation’s capital, had hovered on the edge of a terrible bloody tragedy. Then it was spared.”

Khaalis was convicted of armed kidnapping and conspiracy. He died in prison in 2003.

[Sept. 7, 1977: Hanafis given stiff sentences]

Tuohey, the assistant U.S. attorney, said it is scary to imagine how differently such an attack might end today.

“The current climate doesn’t really permit reasoning. It’s all about blowing it up, and you go with it — it’s the martyrdom,” he said.

Cullinane, the police chief, said he would do it all the same again. “It never entered my mind” to storm the hostage rooms, he said. And if it meant saving the 149 lives, “I would still be talking to [Khaalis] on the phone.”

[Even Hollywood would have called the Hanafi plot outlandish]