In the final months of World War II, a group of Jewish prisoners were forced to cover up evidence of Nazi atrocities.

Shackled by their German captors, 80 prisoners from the Stutthof concentration camp were sent to a site of mass killings in Lithuania. There, they were ordered to dig up the graves and burn the bodies.

At night, the captives were imprisoned in the pit that had been used for mass executions.

Now, scientists using ground-penetrating radar and other high-tech methods have uncovered the tunnel in Ponar that the "Burning Brigade" quietly dug for months using only spoons and their bare hands in an attempt to escape.

The daring plot was launched by a prisoner named Isaac Dogim.

"Dogim had been placing the corpses in layers on the pyre one day, when he recognized his wife, his three sisters and his three nieces ," according to the Holocaust Education & Archive Research Team. "All the bodies were decomposed, he recognized his wife by the medallion which he had given her on their wedding."

While survivors had told the story of the "Burning Brigade" escape after the war, the tunnel itself was not found -- until now.

"As an Israeli whose family originated in Lithuania, I was reduced to tears on the discovery of the escape tunnel at Ponar ," Jon Seligman of the Israel Antiquities Authority, who was on the team that made the discovery, said in a news release.