The standards of rigour in mathematics have increased several times during history. In the process some statements, previously considered correct where refuted. I wonder if these wrong statements were "applied" anywhere before (or after) refutation to some harmful effect. For example, has any bridge fallen because every continuous function was thought to be differentiable except on a set of isolated points?

Sorry if this is a silly question.

The standards of rigour in mathematics have increased several times during history. In the process some statements, previously considered correct where refuted. I wonder if these wrong statements were "applied" anywhere before (or after) refutation to some harmful effect. For example, has any bridge fallen because every continuous function was thought to be differentiable except on a set of isolated points?

Sorry if this is a silly question.

Edit: Let me clarify. I am looking for examples of bad things happening, which fall in the following scheme:

1. Lack of rigour led to a wrong statement (by "today's standard") in pure mathematics.

2. That wrong statement was correctly applied to some other field, or somehow used in calculations etc.

3. The conclusion from item 2 was then applied to a real-world situation, perhaps in construction or engineering.

4. This led to some real-world harm or danger.

It is crucial that there was no mistakes or omissions in 2,3,4, and hypothetical being omniscient on the level of 1 would approve the project.

Sorry if I made it even sillier. Feel free to close the question.