Protesters carry portraits of victims on Oct. 6, during a 40th-anniversary remembrance of the Cubana Flight 455 bombing. (Ernesto Mastrascusa/European Pressphoto Agency)

By noon on Oct. 6, 1976, at Seawell International Airport in Barbados, it was humid, raining and 80 degrees. A McDonnell Douglas four-engine DC-8 jet adorned with Cubana Airlines’ blue, white and red tail sat on the tarmac, just arrived from Port of Spain, Trinidad. It was in the midst of a hopscotch trip across the Caribbean that started in Georgetown, Guyana; was headed to Kingston, Jamaica; and destined for Havana, Cuba.

Among the passengers were 24 teenage athletes. They were members of Cuba’s national fencing team. They caught their country’s flagship airliner in Trinidad after competing in a tournament of Central American and Caribbean countries.

But neither the Cuban fencers nor the other 49 souls on Cubana Flight 455 made it home.

At what must have been the nadir of the U.S. government’s detestation for Fidel Castro, who died last week at age 90 after a lifetime of being a burr in Washington’s saddle on the Western Hemisphere, Cubana Flight 455 exploded in the sky above the Caribbean Sea after two bombs planted by men working for once-CIA-connected, anti-Castro Cuban exiles detonated.

The Cubana Flight 455 mass murder is not seared in our memory like the massacre of 11 Israeli athletes at the 1972 Summer Games. It didn’t play out live on national television like the bloodshed in Munich. It hasn’t been memorialized in dramatic film.

But the two dozen Cuban athletes who perished represent the most horrific attack against innocent sportsmen we’ve ever seen. The downing of their flight remains a rare mid-air bombing of a civilian airliner in the Western Hemisphere.

And the U.S. government’s behavior in the 40-year wake of those deaths remains shameful.

To be sure, just two months ago, on the 40th anniversary of Cubana Flight 455’s downing, the National Security Archive, which has done yeoman’s work on this event, asked the Obama administration to declassify what intelligence records remain on Luis Posada Carriles, the onetime CIA operative convicted in Panama of Cubana 455’s bombing but pardoned in 2004 by then-outgoing Panamanian President Mireya Moscoso, who was supported by Washington. Posada, now 88, resides in Miami.

A 1976 document sent at the time to Secretary of State Henry Kissinger by two high-ranking State Department officials who investigated Castro’s charge that the United States had downed Cubana 455 implicated Posada as the likely planner.

“We have now pursued in detail with CIA (1) what we know about responsibility for the sabotage of the Cubana airliner and (2) how any actions by CIA, FBI, or Defense attache´s might relate to the individuals or groups alleged to have responsibility,” the document stated, “… but any role that these people may have had with the demolition took place without the knowledge of the CIA.”

Posada’s co-conspirator in planning the bombing was Orlando Bosch, who was acquitted in a foreign court of the attack. But a declassified CIA report quoted Posada as saying: “We are going to hit a Cuban airplane” and “Orlando has the details.” An FBI report quoted an informant as saying that one of the men who planted a bomb on the plane called Bosch afterward to tell him that the plan succeeded.

Bosch died in 2011 in Miami, where he lived at least since 1988, when he was arrested there for violating parole. The anti-Castro Cuban community in Miami successfully lobbied President George H. W. Bush, through Jeb Bush, to grant Bosch a pardon on all charges, of which there were many, against him in the states.

Investigations showed that Posada and Bosch had hatched their plan during a meeting in Washington. Posada originally tried to defeat Castro by helping organize the failed Bay of Pigs invasion. After this he became an agent for the CIA, trained at Fort Benning and joined a series of United States-backed efforts to destabilize or overthrow the Castro regime through myriad means, including assassination.

Bosch was not a Bay of Pigs participant but was in constant contact with the CIA in the early 1960s.

The coddling of Posada and Bosch by Washington over the deaths of 57 Cubans, 11 Guyanese and five Koreans aboard Cubana 455 is why the call rejuvenated by some on Capitol Hill, and Gov. Chris Christie in New Jersey, in the wake of Castro’s death that Cuba extradite several U.S. exiles will continue to fall on deaf ears in Havana. The most notable exile is Assata Shakur, the late rapper Tupac Shakur’s step-aunt, who was a leader of the Black Liberation Army in the 1970s when she was convicted of murdering a New Jersey state trooper.

It doesn’t matter that the FBI in May 2013 made Shakur the first woman on its Most Wanted Terrorists list and offered up to $2 million for her capture in Cuba, where for the past 30 years she’s lived more quietly in an apartment in Havana, where I met her in 1989, than Posada and Bosch have and did, respectively, in Miami. The wound in Cuba of Oct. 6, 1976, trumps the lack of an extradition treaty between Washington and Havana.

Peter Kornbluh, who has researched and written extensively about the Cubana 455 incident as a senior analyst at the National Security Archive at George Washington University, said he thought of the event again this week after a charter jet carrying a Brazilian soccer team among its 77 passengers crashed Tuesday in Colombia. Seventy-one people on board were killed.

“The first thing I thought of when I heard of this [Brazil] horrible crash, the loss of that team, is the way the Cubans must have felt,” Kornbluh told me Friday.

“Their [Cuban] team was coming back from a competition they’d done very well in,” he recalled. “The Cubans took great pride in their young people. There were six young Guyanese medical students on that plane. Fidel had offered medical scholarships to those students.

“You do get a sense of how anguished the Cubans must have felt when that plane went down. And it wasn’t an accident; it was an act of terrorism. So it was even more painful and outrageous.”

Kevin B. Blackistone, ESPN panelist and visiting professor at the Philip Merrill College of Journalism at the University of Maryland, writes sports commentary for The Washington Post.