A note hidden in a bottle by Auschwitz prisoners 65 years ago in a desperate attempt to preserve a small piece of themselves was added Wednesday to the archives of the Polish state-run museum dedicated to the memory of the former Nazi death camp's victims.

Museum Director Piotr Cywinski hailed the document — a list of the names of seven camp inmates that was discovered last month — as a rare discovery and a cause for celebration, given that at least three of the prisoners are still living today.

"This is a very clear sign of hope," Cywinski said. "These young people put the message in a bottle to leave a sign. But not only the bottle survived — some of them also survived. This is very moving."

The note, written in pencil on a scrap from a cement bag, was discovered by a construction crew renovating a cellar that was used by Nazis during World War II as a bunker and place to store food. The building is now on the grounds of a vocational school in Oswiecim, a town the Nazis called Auschwitz, whose director handed the note over to Cywinski in a ceremony.

One of the survivors, Waclaw Sobczak, recalled that he and his fellow inmates never expected to survive the camp and wanted to leave behind a trace of their lives.

"We did it so a sign of us would remain after we died," said Sobczak, a diminutive 85-year-old with thick white hair. "It was very risky and we had to be very careful putting it in the wall. We wanted at least our names and numbers to be left behind."

Dated Sept. 20, 1944, the note bears the names, camp numbers and hometowns of the seven prisoners — six Roman Catholics from Poland and one Jewish inmate from France. It says that all were between the ages of 18 and 20 and assigned to build an anti-aircraft bunker for camp commanders.

"We agreed that we may not survive and that we will make this message in the bottle, and that we will put down our names and camp numbers and we will leave it in the bunker wall," Sobczak recalled in a brief speech at the handover ceremony.

He said he was "happy and satisfied" to hear the bottle was found, even though it brought back sad memories of the suffering that he endured and witnessed during 18 months as an Auschwitz inmate. He said he either placed it in the wall himself or covered it in cement, but can't remember exactly anymore.

The other two known survivors are Albert Veissid, a French Jew, and Kazimierz Czekalski, a Pole from the city of Lodz.

The others on the list are Bronislaw Jankowiak and Stanislaw Dubla, who both died after the war, while nothing is known of the fate of two more, Waldemar Bialobrzeski and Jan Jazik.

At least 1.1 million people, mostly Jews — but also non-Jewish Poles, Gypsies and others — died in Auschwitz-Birkenau's gas chambers, or from starvation, disease and forced labor, between 1940 and its 1945 liberation by Soviet troops.

Cywinski said most surviving documents from Auschwitz were produced by the Nazis.

"We don't get many documents written by inmates. It's rare," he said.

He also appealed to the wider public to hunt through their attics and basements to see if more such documents still exist.