Germany on Wednesday marks the 40th anniversary of the Munich Olympics massacre amid fresh questions about how the 11 Israeli victims could have been killed on German soil.
A tribute to the victims will be held at 1400 (GMT) at the Fuerstenfeldbruck air base, west of Munich, site of the tragic climax of the bloody hostage-taking by members of a radical Palestinian group known as "Black September".
Seven Israeli survivors as well as around a dozen relatives of the slain Olympic team members will join about 500 political and sport officials including German Interior Minister Hans-Peter Friedrich.
The southern state of Bavaria has ordered flags on public buildings to be flown at half-mast and pictures of the victims will be exhibited for the first time at the former air traffic control tower at Fuerstenfeldbruck.
The ceremony marking the worst violence at any Olympics to date will culminate in an ecumenical memorial service in the presence of a rabbi.
The sombre anniversary has given rise to new research into the horrifying chain of events at the 1972 Games, which were meant to showcase the new face of Germany nearly three decades after Second World War.
Gunmen broke into the Israeli team's flat at the Olympic village, immediately killing two of the athletes and taking nine others hostage to demand the release of 232 Palestinian prisoners.
A bungled rescue operation resulted in all the hostages being killed along with a West German policeman and five of the eight hostage-takers.
The news sent shockwaves through Germany just 27 years after the Holocaust and opened a deep rift with Israel.
Last week, Israel released 45 official documents on the killings, including specially declassified material, which lambasted the performance of the German security services.
Included in the reports is an official account from the former Israeli intelligence head and his heavy criticism of the German authorities for the failure of their rescue operation.
The German police "didn't make even a minimal effort to save human lives," former Mossad head Zvi Zamir said at the time after returning from Munich.
He said elite German snipers had been equipped only with pistols, and that personnel carriers meant for the rescue operation had arrived late.
"They had no follow-up plan, nor any means of improvising an alternative," he said.
The files also show evidence of failures by the Israeli security forces.
Meanwhile in Germany, investigative news weekly Der Spiegel threw its spotlight on the violent proceedings of that late summer day, accusing the German government and Olympic organizers of covering up grave mistakes.
Months before the hostage taking, the German interior ministry and the Bavarian state police warned federal authorities in vain of the possibility of "terrorist acts" at the Games, the magazine said.
The Spiegel report recalled that the Olympic village was surrounded by a simple chain link fence without security reinforcements.
The head of the Munich police evidently feared that a robust security presence would revive ugly memories of the 1936 Games in Berlin, presided over by Adolf Hitler.
And even the head of the West German Olympic Committee, Willi Daume, snapped at his security chief that he had no intention of making the Olympic village look like a "concentration camp".
The 40th anniversary already gave rise to anger and recriminations this summer during the London Games.
Two widows, Ankie Spitzer and Ilana Romano, had unsuccessfully campaigned for the anniversary to be marked with a minute's silence at the opening ceremony in the British capital, a request rejected by IOC President Jacques Rogge.
As a conciliatory gesture, a minute's silence was held instead at the Olympic village in London for the signing of the Olympic truce on July 24.