What happens after the first peak?

This isn’t the first outbreak that we’re going to be dealing with. Remember that we’re nowhere near herd immunity in Miami Beach and most of us are still vulnerable. There will be another outbreak when people start to travel and visit our town again.[1]

If control of the first outbreak depleted resources—such as drug stockpiles or ‘goodwill’ among the population to follow quarantine measures—the second outbreak will be largely uncontrolled, producing a significant overshoot.
Tanaka MM, Althouse BM, Bergstrom CT. Timing of antimicrobial use influences the evolution of antimicrobial resistance during disease epidemics. Evolution, Medicine, and Public Health; link

Meaning that many more people would die, in total.

White House health advisor Dr. Anthony Fauci has explicitly warned that there is a “likelihood” of a second wave if areas of the US reopen too soon, while the virus is still spreading and while adequate testing is not yet in place. [2]

If I were advising [Georgia Gov. Brian Kemp], I would tell him that he should be careful and I would advise him not to just turn the switch and go because there is a danger of a rebound, I plead with the American public, with the governors, with the mayors for the people of your responsibility, although I know one has the need to leap frog over things, don’t do that. Do it in a measured way. This is a successful formula. The problem is if we don’t do that, there is a likelihood that we will have a rebound.
Higgins-Dunn N, Kolodny L. Trump says he ‘totally disagrees’ with Georgia Gov. Kemp’s decision to reopen businesses in the middle of coronavirus pandemic. CNBC; link

References

  1. 1. Tanaka MM, Althouse BM, Bergstrom CT. Timing of antimicrobial use influences the evolution of antimicrobial resistance during disease epidemics. Evolution, Medicine, and Public Health; link
  2. 2. Higgins-Dunn N, Kolodny L. Trump says he ‘totally disagrees’ with Georgia Gov. Kemp’s decision to reopen businesses in the middle of coronavirus pandemic. CNBC; link