Friday off-topic. How to survive in a falling elevator...
...The best possible option may surprise you. And no it's not the most obvious one, namely jumping at the moment of impact. You can't possibly guess the exact moment of impact, and you'd still end up falling heavily on your feet (or some other part of your body that you can't anticipate).
Standing up straight turns out to be a bad option too. Best way:
Lie flat on your back on the floor. Why? You'd spread the impact across the surface of your body. Unless parts of the floor decide to splinter and impale you, of course.