While it may have been the furthest point from the fire, it was not smokeproof
. For those who chose to stay, the decision proved fatal, and many workers were saved after jumping into the sea.
The IBC has required exit stairways in high-rise buildings to be protected as smokeproof enclosures or pressurized stairways since its inception.
As an alternative to smokeproof enclosures, pressurized stairways can be used in sprinkler protected buildings without incorporating the ventilated vestibule.
The IBC currently requires stair towers in high-rise buildings to be "smokeproof
" towers, and allows the use of an open breezeway (natural ventilation), an intermediate vestibule, or a pressurized tower to satisfy the requirement.