I think this counts: https://en.wikipedia.org/wiki/Black_Death https://en.wikipedia.org/wiki/Black_Death The Black Death is estimated to have killed 30–60% of

I think this counts: https://en.wikipedia.org/wiki/Black_Death https://en.wikipedia.org/wiki/Black_Death The Black Death is estimated to have killed 30–60% of Europe's total population. In total, the plague may have reduced the world population from an estimated 450 million down to 350–375 million in the 14th century. It took 200 years for the world population to recover to its previous level. A modern pandemic would spread much faster due to modern transportation, and while modern medical science would help at first, medical services would quickly become overwhelmed. If critical infrastructure starts failing due to lack of workers (either they are sick or staying home to take care of family or avoid the illness), then things will get much worse very quickly. Assuming you escape infection, having a secure isolated bunker with a couple years of food may actually help you survive.