be the death of

1. Cause the death of something or someone, as in This comedian is so funny, he'll be the death of me. Although this phrase can be used literally, meaning “to kill someone or something,” it has also been used hyperbolically (as in the example) since the late 1500s. Shakespeare used it in 1 Henry IV (2:1): “Since the price of oats rose, it was the death of him.”

Example Sentences

"Europe is in serious trouble. They have been invaded by a force of illegal aliens like nobody has ever seen before… Both the immigration and suicidal energy ideas will be the death of Western Europe," he said.

From BBC

This bullpen is going to be the death of them.

From Los Angeles Times

Moore never considered that “Long Bright River,” which ended up on Barack Obama’s favorite books of 2020 list, would become a series when writing — that idea, she says, would be the “death of my fiction.”

From Los Angeles Times

She’s saying this could be the death of democracy.

From Slate

This is an open wound which is bleeding profusely and if not addressed, could be the death of the patient.

From Salon