It happened during the Spanish flu, it really did. The year my mother was born. People symptom-free in the morning; dead before dinner. Once the aveoli get clogged and stop functioning, it doesn’t take long. This is not an influenza, it is a corona virus, but the effects of the resulting viral pneumonia appear to be the same. See my other comment on the NAC supplement to keep the lungs functional for as long as possible.
You’re giving me flashback shivers. I had viral pneumonia about ten years ago, it nearly dropped me and it was over three months before I felt half human again. I don’t think I will survive another round.