Don't Look Down (1998)

Carla's sister accidetally falls off a cliff when the railing becomes loose while Carla's boyfriend takes photos. She has a hard time getting over her death and keeps having visions of her sister yelling at her for not saving her. It seems that everytime she gets next to a edge of a high area, she gets terrified. She then starts to take a class with other Acrophobiacs. Then the people in the group start getting killed one by one. She starts to suspect that someone wants her never to get over her fear and that the loose railing was meant for her.