The two following testaments were written by Jewish prisoners in the Chelmno death camp and found there after the war.
Herszkowicz, Josef of Kutno
These are the last Jews who worked for the Gestapo in Chelmno, which is situated between Dabie and Kolo. These are the last days of our lives so we give a signal maybe there still will be relatives or acquaintances of these persons. So you shall know all Jews who were sent away from Litzmannstadt (Lodz) were killed in a very cruel manner they were tortured and burnt goodbye if you survive you must take revenge.
This note is written by people who will live for only a few more hours. The person who will read this note will hardly be able to believe that this is true. Still, this is the tragic truth, since place your brothers and sisters stayed, and they, too, died the same death! The name of this locality is Kolo. At a distance of 12 km from this town [Chelmno] there is a 'slaughterhouse' for human beings. We have worked here as craftsmen there [illegible word], I can give you their names.
Pinkus Grun of Wloclawek
These are, then, the persons' names which I give here. These are only a few people from among the hundreds of thousands who died here!
From: Kleinman, Yehudit and Dafni, Reuven (Eds.). Final Letters From the Yad Vashem Archive, London, 1991.
Sources: Yad Vashem - Eclipse of Humanity