[red_admiral]

Yes, a lot of modern engineering is good enough that single-cause failures are very rare indeed. That means that failures themselves are rare, but when they do happen, they're most likely to have multiple causes.

How to explain that to non-engineers is another problem.

[pseudohadamard]

I think a better way of explaining it to people is that we've made critical systems so reliable that, in order for them to fail, the failures have to be quite complex.

[cameldrv]

This is almost universal in aviation. They always talk about the "accident chain." Essentially everything that can kill you with one mistake is illegal through training and operational requirements and engineering and maintenance regulations.

[javier2]

we are not as complicated as the national grid, I have been here for nearly 10 years now, and our outages have gone from single cause, two causes, or now its nearly always 3 things that need to go wrong at the same time.