If MWI is correct, every deadly quantum event in this experiment is a branch in which two different universes exist: one with you, and one without you. Since yo

If MWI is correct, every deadly quantum event in this experiment is a branch in which two different universes exist: one with you, and one without you. Since you can only observe the ones in which you still live, it seems to you that this event stops happening with deadly certainty as soon as you are in the box. When you leave the box, it starts happening again. Repeat as many times as you like, the results are the same. Put someone else in the box, they inevitably die in a few seconds. What is the other possible explanation?