To limit the probability that fire escapes will be of a stair type not extending to ground level, which could lead to delays in the evacuation or movement of persons to a safe place in an emergency situation, which could lead to harm to persons.
To limit the probability that fire escapes will be of a stair type not extending to ground level, which could lead to emergency responders being delayed in gaining access to fire escapes in an emergency situation, which could lead to emergency responders being delayed or ineffective in carrying out their emergency response operations, which could lead to delays in the evacuation or movement of persons to a safe place, which could lead to harm to persons.