Thus, children or adults may venture innocently into an area that has old cave-ins and shafts. People should remain on marked trails. This has happened in some of the oldest mined areas. In areas where mining is known to have taken place in the 1800s, such as parts of Michigan, openings such as pits or crevices should always be avoided. Children should be warned to stay away from such openings.
Many open pits exist in mining areas.
Pit walls may be unstable and landslides may occur at any time. There may be overhanging edges on pit walls that could collapse when a person stands on them. The walls of the pit may be steep. Persons have drowned in the water in these pits because the water may be deep all around the pit with no ledge or place to hold on to. Diving into a pit is dangerous because there may be rocks just below the water surface.