If you're afraid of this kind of thing, then don't use escalators when they aren't moving, that's fine.

According to a quick Google search, there are 2-3 escalator related deaths per year in the US. That's not just counting malfunctioning escalators, it also counts morons doing dumb things on escalators (and "within the US" includes every Florida Man out there).

You can worry about this if you like worrying, but it's probably not worth it.