Many people who would hesitate to look over the side of a tall building do not show any fear when looking into a mine shaft. The fall down a mine shaft is just as lethal as the fall from a tall building - with the added disadvantage of bouncing from wall to wall in a mine shaft and the likelihood of having falling rocks and timbers for company. The timber in abandoned mines are unsafe. Ladder rungs are often missing or broken. Some will fall under the weight of a child because of dry rot.
Vertical ladders are particularly dangerous.
It is impossible to climb down a vertical ladder and examine each rung before placing weight upon it. This danger is not apparent as the lumber often looks very solid-when it actually can be crushed with the squeeze of a hand. Other timber, although in good condition. A mine shaft will weather in much the same way as a cliff. There are always loose rocks on timbers or on the walls.