Kurt Prüfer's arrest on May 30, 1945 led Ludwig Topf to fear arrest himself. That same evening, he decided to commit suicide. In a farewell letter he cast himself in the role of a person guilty of nothing and wrongly persecuted. He disinherited his brother Ernst-Wolfgang and his sister Hanna who, he felt, had abandoned him. On the morning of May 31, 1945, at the age of 41, Ludwig Topf committed suicide by taking poison.

Farewell letter by Ludwig Topf, May 30, 1945 (excerpt, underlining in original)

"If I have made the decision to evade arrest it is for the following reason: I have lost all belief in any law in this world now that my family has also done me so much wrong and harm. If I am arrested, the greatest of all wrongs will be done to me. I never consciously or intentionally did anything bad; instead it has been done to me.
I was never cowardly – but I was proud. Handing myself over to the mercy or mercilessness of a foreign country is something I cannot do, because I have learnt the bitter lesson that there is no law and no decency left in this world. That is why I, as a decent person, today have one remaining opportunity to determine my fate as I see fit. And that means immediate departure from a world that in general has become unbearable, and in particular has persecuted and wronged me.
If I ever believed that my innocence as far as the crematoria are concerned (and my brother is just as innocent) would be recognized and honoured, I would continue to fight for justification, as I always have until now – but I think people need a sacrifice. In which case the least I can do is provide it myself. I was always decent – the opposite of a Nazi – the whole world knows that. If I were still able to feel at peace in the heart of a family, the struggle would be worthwhile – but the Topf family that showed composure, integrity and self-confidence has ceased to exist. I was its sole representative as far as that was concerned. Indeed I am so alone that I have no need to ask anyone's forgiveness, not even for a suicide."