it happens...she probably didn't or couldn't let go ...arthritis maybe...but escalator are nothing to play with. When I worked in the industry, I heard people call them meat grinders bc they do not stop unless the safetys are tripped. even though they are design to trip, sometime they don't...they will remove a arm or leg or foot if not careful. I see one grind a shoe to nothingness....be some dumb teenage was playing on the escalator and got it caught.