Humankind is on a slippery slope to extinction if people fall down holes and blame others for it. She should look where she's walking.
People can't expect to be wrapped in cotton wool all their lives.
It's a big deal to leave a manhole uncovered. What if a blind person fell in? Would it be his fault for not being able to see the open manhole in front of him?
EDIT: Oops, this has already been mentioned. Should have read the whole thread before commenting, sorry.