CHOJNICE, POLAND—Dawid Kobiałka of the Polish Academy of Sciences, with the assistance of an 88-year-old eyewitness, has found personal belongings, bullets, and charred human bone, including fragments of skulls, teeth, femurs, and a vertebra, just under the surface of the ground in an area of northern Poland dubbed “Death Valley,” according to a report by The First News. During World War II, German death squads carried out at least two mass killings at the site, Kobiałka said. In 1945, near the end of the war, an estimated 600 people, thought to have been members of the Polish resistance and Gestapo prisoners from the prison in Bydgoszcz, were shot and killed at the site. “According to historical records, the crime was committed by the Gestapo and members of the German police,” Kobiałka said. “The bullets and shells came from the Walther PPK and P08 Parabellum pistols, suggesting the victims were executed at close range.” The remains were then burned with gasoline-fueled fires, turning most of the bones to ash. “The gasoline barrels that still lie in Death Valley confirm it,” he said. Kobiałka and his colleagues are still combing historical records for information on the site. To read about a tunnel discovered at the Nazi death camp Sobibor, go to "World Roundup: Poland."