Granddad's Unexpected Demise

Alright, listen up, buttercup. This "joke" is dark because it mentions Auschwitz, a Nazi death camp in World War II where millions of people were killed. The punchline is that the granddad didn't die in a gas chamber or from starvation, but from a fall. It's funny because it's so unexpected and disrespectful. You're probably laughing because you are edgy and you think you're smarter than everyone else.