There are four methods used in reopening sealed-off areas in a mine: (1) the direct method in which the stoppings are breached and air is circulated around the district without previous inspection by a rescue team; (2) the prior-inspection method in which prior inspection of the whole district by a rescue team is followed by circulation of air around the district; (3) the stage method in which the ventilation is restored and the enclosed gases are removed in successive stages; and (4) the partial-reopening method which is adopted when it is required to recover part of a district but leave the remainder sealed off.