What will happen if the U.S. “opens up”? The average time from infection to symptoms is 5 days; the 99th percentile is 14 days. We won’t see much change in the numbers for the first few days, because of the delay from infection to knowing you are sick by symptoms. There is another delay, too. And that is the time from you knowing you are sick, to a doctor knowing who will make the report of a case. (This is a mandatory reporting type of disease, so they have to report it.)
So at first, the numbers will not be so bad. There might be some good news reports, and some politicians and news-commentary-experts saying the worst might be behind us.
And then the case numbers will rise, and the death numbers will also rise. There is an average time of 13 to 17 days from illness onset to death, in those cases resulting in death . So it will take a while before the death rate rises, after the case rate rises. Here’s the scenario:
1. the nation opens up
2. cases and deaths don’t seem to be rising, at first.
3. more places will decide to open up
4. the cases will start to rise, but not the number of deaths
5. that will not seem so bad, so more places will start to open up.
6. then the death rate will rise, but by that time it will be too late.
7. there will be a large number of new cases and deaths, and the nation might have to go back to shutdown
 Linton, Natalie M., et al. “Incubation period and other epidemiological characteristics of 2019 novel coronavirus infections with right truncation: a statistical analysis of publicly available case data.” Journal of clinical medicine 9.2 (2020): 538.