Israeli and German government officials are planning to mark the 40th anniversary of the massacre of Israeli athletes at the Munich Olympic games of 1972.

On September 5 of that year, Palestinian Liberation Organization (PLO) gunmen shot and killed 11 Israelis they had kidnapped from the Olympic Village. The Palestinians had demanded the release of 200 Arab prisoners from Israeli jails in exchange for the athletes’ freedom.

In the ensuing chaos and bungled rescue attempt, five of the Palestinians and one German police officer were also killed.

A group of German politicians, including Munich Mayor Christian Ude, and Israeli survivors of the killings will assemble at Fuerstenfeldbruck, the airport near Munich where most of the Israelis were murdered.

Israeli Deputy Prime Minister Silvan Shalom will also attend the ceremony.

"We are coming here not just to remember, but also to see the future, [so] that it will not happen again," said Dan Alon, an Israeli fencer who participated in the 1972 Olympics.

The German state of Bavaria also ordered that flags at public buildings fly at half-mast.

Despite Germany’s observance of the memorials, questions have arisen over security measures that West German officials took -- or failed to take -- ahead of the 1972 killings.

According to declassified Israeli documents, Israel’s intelligence blamed West German authorities for failing to provide sufficient security at the Munich games.

Zvi Zamir, the former head of Mossad, Israel’s spy network, lamented that the West Germans "didn't make even a minimal effort to save human lives.”

Even more alarming, West German authorities might even have been aware that terrorists were planning to strike the 1972 Games.

According to Germany’s Der Spiegel magazine, classified documents indicate that West German officials had ignored explicit warnings of a terrorist attack at the Olympics and even tried to cover up their subsequent security failures.

The German publication reported that both local Bavarian and federal West German government officials had received warnings that the PLO’s “Black September” group might engineer an attack against Israelis at the Olympic Village and did nothing to prevent it.

As early as mid-August 1972, a German official at the embassy in Beirut, Lebanon, heard that "an incident would be staged by the Palestinian side during the Olympic Games in Munich." Shortly thereafter, the West German foreign office sent a notice to Bavaria’s state intelligence agency to "take all possible available security measures" against such an attack.

Even the press reported on such rumors ahead of the Games.

On September 2, just 72 hours prior to the kidnappings and murders, the Italian publication Gente reported that Black September terrorists were plotting a "sensational act during the Olympic Games."

In preparation for the criticism that West German officials would likely receive in the wake of the killings, an official of the foreign ministry reportedly told cabinet ministers: "Mutual incriminations must be avoided. Also, no self-criticism."