YANTARNY, Russia, Jan. 30— At the start of the death march in Konigsberg, they numbered about 7,000 -- the vast bulk of them women, most quite young, all clad in wooden-soled shoes, thin rags emblazoned with yellow six-pointed stars and telephone wire belts on which were strung their cups and tin-can bowls.

By the time they reached a vacant lock factory in this nondescript seaside village, after two days and 25 miles of brutal winter weather, there may have been 4,000 left. They remained perhaps four days, then were herded down a bucolic cobblestone lane and past dilapidated workers' cottages to an abandoned amber mine on the shore of the Baltic Sea.

It was there, 55 years ago Monday night, that SS guards split them into packs of 50, sent them fleeing down the beach and on to the ice-covered water itself, then mowed them down with machine guns. Others were escorted to the mine and shot point-blank.

Auschwitz had been liberated four days before. ''Never forget,'' the civilized world said.

But the world forgot about the massacre of Jewish innocents at Palmnicken, now the Russian town of Yantarny, until today. Today, on the beach, a roaring gale whipped the sleet into needles and raised towering whitecaps on a sea the color of wet cement. At the base of the amber mine, a steep concrete-buttressed cliff resembling a battlement, about 200 mourners dedicated a small pyramid of stones and a plaque to the victims of the Konigsberg march and the Palmnicken massacre.

They were the first tangible recognition that the march and massacre had ever occurred. Until today, there was no memorial to Holocaust victims anywhere in Konigsberg -- known now as Russian Kaliningrad -- even though it was home to several small concentration camps.

Astoundingly, the whole of the Kaliningrad region -- a million people, the eldest of whom fought valiantly to defeat Hitler's army in World War II -- was utterly unaware until a year ago that the massacre had ever taken place. ''As far as I know, no one needed this,'' Rabbi David Shvedik of the Jewish Community of Kaliningrad said in an interview. ''For the authorities in Yantarny and in the region, it was not at all interesting to them to remember 7,000 dead Jews.''

The story of the massacre, and of Kaliningrad's slow awakening to it, is at once riveting and chilling. Put simply, the victorious Soviet Union closed the book on Nazi atrocities once it seized Konigsberg from the Germans at the end of World War II. Thousands of Germans were deported in rail cars to be replaced by Russian immigrants; Jewish Holocaust victims were reburied as ''Soviet heroes,'' stripped, here and elsewhere on Soviet soil, of religious identity. Red Army reports on the massacre and on the discovery of mass graves were written, filed and classified.

Kaliningrad became a Soviet naval base and a closed region, steeped in secrecy. Horrific memories half-lived into rumor, then myth, then taboo enforced by the Kremlin's own unspoken, unofficial anti-Semitism.

''As far as I know, not a single person was ever sentenced for this,'' said Aleksandr Aderichin, the investigative editor for the Kaliningrad newspaper Dvornik, which helped awaken the region to the massacre story more than a year ago.

That Kaliningrad awakened at all may be credited to Christians -- a German and an American -- who grew up near Palmnicken and would not suppress their own memories of the slaughter. The German, Martin Bergau, witnessed the executions of some women and gave harrowing testimony to them in a German-language book and in a submission to Yad Vashem, the Holocaust Remembrance Authority in Jerusalem.

The American, Gunter Nitsch, had only heard stories of the killings as a boy. But as an adult, he was so haunted by the massacre's specter that he was compelled to track down the truth -- and in the process, to unleash the long-hidden accounts of what happened.

''I feel awful,'' Mr. Nitsch said last week in a long telephone interview. ''These were my people. Most of the people in my family were members of the Nazi Party. Whatever happened cannot be changed. But it must not be forgotten.''

Mr. Nitsch, now 62, was a 7-year-old when the Red Army stormed through Poland and into Konigsberg in early 1945. As the Communists moved north, the Nazis began vacating a network of 30 camps ringing Poland's Stutthof concentration camp, moving 20,000 Jews away from the advancing army. Ninety percent were women and most were from Hungary and Lithuania.

The fate of all 20,000 is unknown. What is clear is that roughly 7,000, by the latest estimate, wound up at a sub-camp in Konigsberg, a Baltic port, in January weather so unusually bitter that ice floes stretched hundreds of feet from the shore. On Jan. 26, Nazi guards began marching the crowd, clad only in rags, 25 miles northwest to Palmnicken.

Perhaps one to two thousand or more died along the way, either of exhaustion or execution as they tried to flee their torturers. ''We marched in heavy snow,'' Dora Hauptman, one of the captives, told Yad Vashem in 1994. ''The cold was fierce, and a freezing wind blew.''