Falls are also deadly. Rock climbing in a mine or quarry is especially dangerous. The rock of a high wall or a mine has been fractured by blasting and can be highly unstable. The rocks that the climber depends upon for support can break free, or the climber’s weight can destabilize an entire face of rock. Falls also occur in underground mines when the victim walks across rotted timbers covering a vertical shaft or steps over a ledge while negotiating a dark area.