I think it is always a possibility in spite of careful design. I once saw a woman walk around the bow of a ship sailing into a rather stiff wind. As she rounded the bow the reverse wind hit her and knocked her to the deck and she started to roll. At that point, in the particular ship we were on, the lower portion of the railings were solid metal, but a little further on they were open at the bottom. She rolled awfully close to the open area. So very scary and quick, I have never forgotten.