Not one big enough to cause another great extinction, but small enough to just turn a whole small country and parts of neighboring ones into a huge crater. Will the people who was evacuated out after NASA stated a warning try to rebuild the country after everything has settled down or do they’d become citizens of another country?
Edit: after reading the comments, maybe turning a small country into a crater is too much, what about just level the place, or in any way that make it uninhabitable for a period of time?
I don’t really subscribe to the whole if civilization collaspes there will be no technology in anyone’s lifetime again thing. You aren’t going to go back to ordering shit off amazon from your smartphone or anything. However the knowledge that things like refrigeration, radio transmission, internal combustion engines, water treatment and such are possible is going to drive people to eventually find out how to get it by any means necessary.
How quickly this happens is a question of whether the majority of people adopt a “technology is too dangerous/a sin against God” idealogy or not.
One of the things missing from this step are all the incremental progress that is the best we can do at given levels of technology. I know LED lights exist and will help us extend our limited energy - but how does that help us with the necessary materials science, integrated circuits, fabs, or even how to build a reliable incandescent light in the meantime