After Gusta Davidson Draenger, a courier in Kraków known by her Polish alias, Justyna, was captured, she wrote her story on pieces of paper smuggled into her prison cell. She described the harrowing trips she and the other couriers made:
When they heard about mass shootings or death camps, Jews in ghettos struggled to figure out how to respond. Many Jews who heard these stories simply could not believe them or assumed that the escapees who told them had lost their minds. Most believed that Jews who had disappeared or been arrested had been sent to labor camps, not murdered.
In 2001, Holocaust scholar Michael Berenbaum interviewed two Jews who lived in the Warsaw ghetto in 1942—Marek Edelman and Simcha Rotem (or Kazik, as he was then known). Berenbaum asked what Edelman, Kazik, and other Jews had known about the fate of Jews who were deported from the ghetto. Were they aware of Treblinka, a killing center only 80 miles from Warsaw that opened in 1942 Berenbaum recounts:
Edelman corrected me. The issue was not Treblinka. It was Chelmno, where gassing began . . . a full eight and one-half months before the deportations [from Warsaw]. Two men escaped from Chelmno, and they reported . . . mobile gas vans killing people with exhaust fumes. Warsaw Judenrat [Jewish Council] leader Adam Czerniakow knew what was happening. But he suspected, or so Edelman was told, that . . . “it was impossible that such a thing could happen in Warsaw” . . .
The “street,” to use Edelman’s terms for the ghetto, was not convinced about gassings at Chelmno. . . . “There is a war,” they were saying. “Germans need a big labor force. Jews are a free labor force. There is no reason to kill them.” In short, logic dictated that Jews be kept alive. But the killing of the Jews was ideological, which overrode the logic of the war.
Nevertheless, I pressed on Treblinka.
Kazik’s recollection was specific. . . . When the deportations [from Warsaw] of July 22  began, [the Jewish resistance movement] was anxious . . . to learn about Treblinka, the destination of the transports leaving the ghetto. Zygmunt Frydrych, a member of the resistance who had connections with railway men . . . was able to board one of the trains and to head toward Treblinka. He could not enter the camp, but rather reached the Malinka stop, where he proceeded to speak with the railway men. Trains were arriving daily, he was told. This bit of information he already knew. The trains were filled with Jews. That, too, he knew. They arrived in the station filled; they left empty. No food was brought into the camp, and no wells had been dug to provide water. This information was new. . . .
The trains were arriving full, leaving empty, with no provisions made for the passengers . . . who had arrived at their destination. They were being left without food and water. At best, they would be starving. . . . Starvation was passive violence, eliminating those who were unfit without being forced to take any direct action.
“The camp was silent,” Frydrych was also told. Tens of thousands arrive. They enter. There are no provisions for their survival, and they make no noise.
In retrospect, we clearly know how to piece together each bit of information, but Frydrych’s assignment was to learn what had happened to the Jews, to do so directly so that he could be clear . . . in his report to the ghetto about the fates of those who had been forcibly evacuated. Still, he had not seen with his own eyes what was happening. . . .
Early the next morning, as Kazik described it, Frydrych wandered around Malinka and saw a dazed man in his underwear, walking around, yet wearing no clothes.
Edelman added, “It turned out that [the man] was his friend . . . ; his name was Walach.” Walach told of his escape from Treblinka on one of the trains that had brought Jews to the camp. He described in detail the gassing and the killing, so Frydrych had finally gotten his eyewitness report. Still he wanted more.
How was he to know what had happened, to know directly, to convince those who were skeptical back in Warsaw or those so desperate that they would still then deny what was happening?
“Take a deep breath,” Frydrych was told. The smell of burning flesh was unmistakable, undeniable. Frydrych had his confirmation. With this, he could return home to bear witness, to assume the task of convincing colleagues that resettlement was death and Treblinka was an extermination center.