Death may come through starvation, thirst, or gradual suffocation. The timber in abandoned mines can be weak from decay. Other timber, although apparently in good condition, may become loose and fall at the slightest touch. A well-timbered mine opening can look very solid when in fact the timber can barely support its own weight. There is the constant danger of inadvertently touching a timber and causing the tunnel to collapse.
Poisonous gases can accumulate in low areas or along the floor.
A person may enter such areas breathing the good air above the gases but the motion caused by walking will mix the gases with the good air, producing a possibly lethal mixture for him to breathe on the return trip. The result is dizziness, followed by unconsciousness. If the gas doesn't kill, the fall will. This is extremely dangerous. Explosives should never be handled by anyone not thoroughly familiar with them.