The note, written in pencil then rolled up and inserted in a bottle, contains the names of seven young people who probably thought they were doomed to die in the notorious Auschwitz death camp.
A construction crew renovating a cellar near the Auschwitz site discovered the bottle hidden in a concrete wall, officials said Monday.
Dated Sept. 9, 1944, the note bears the names, camp numbers and hometowns of the seven prisoners — six from Poland and one from France.
"All of them are between the ages of 18 and 20," the final sentence reads.
"They were young people who were trying to leave some trace of their existence behind them," said Auschwitz museum spokesman Jaroslaw Mensfelt. He said two of the prisoners survived the camp but he did not have further details.
Workmen were tearing out a wall in the basement of a college building in the town of Oswiecim — which was called Auschwitz by the Nazis during World War II — on April 20 when they discovered the bottle, college spokeswoman Monika Bartosz said.
She said the note appeared to have been written on a scrap from a cement bag.
The school's three buildings, which are a few hundred meters (yards) from the camp, were used as warehouses during the war by Hitler's SS troops. The prisoners were compelled to reinforce the cellar with concrete so it could serve as an air-raid shelter.
Museum experts have verified the authenticity of the note, which will be handed over to the museum in early May.
The Nazis set up the Auschwitz camp in 1940 in occupied Poland. 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, before Soviet troops liberated the camp on Jan. 27, 1945.