It's the summer, and Liesel isn't having a bad time.
For Death, "the sky [is] the color of Jews" (52.3).
Death takes the souls of the Jews "out of the shower facilities" and out into "eternity" (52.4).
Many Jewish people were gassed with Zyklon B, after being told they were entering shower facilities (source).
Death can't forget the first visit to Auschwitz or the first visit to Mauthausen. (These are names of some Nazi concentration camps.)
Death takes Jews who jump from cliffs rather than face the gas.
It makes Death cold to remember, and Death "[tries] to de-realize it" (52.6).
(What do you think Death means by "de-realize"?)
Death says "God." He tells us that God doesn't answer him, no more than God answers humans.
Death can't understand why this is happening, and it makes Death so tired to think about it.
On June 23, Death takes French Jews from a German prison in Poland.
[Poland and France are both occupied by the Nazis at this time. An estimated 25 percent of France's Jews were murdered during the Holocaust (source).]
Please believe me when I tell you that I picked up each soul that day as if it were newly born. […] I listened to their last, gasping cries. Their vanishing words. I watched their love visions and freed them from their fear. (52.15)
Death is in dire need of something to blunt the intensity. Even the clouds seem on the run from the scene.
Of the dead Death takes this day, Death says, "They were French, they were Jews, they were you" (52.18).