FEMA 453 Design Guidance for Shelters and Safe Rooms

The 48 seconds do not include the time prior to entering
the stairwell, which was often substantial. Some occupants
delayed or interrupted their evacuation, either by choice or
instruction.
m Downward traveling evacuees reported slowing of their travel
due to ascending emergency responders, but this counterflow
was not a major factor in determining the length of their
evacuation time.
m Approximately 1,000 surviving occupants had a limitation that
impacted their ability to evacuate, including recent surgery
or injury, obesity, heart condition, asthma, advanced age,
and pregnancy. The most frequently reported disabilities
were recent injuries and chronic illnesses. The number of
occupants requiring use of a wheelchair was very small.
m Mobility challenged occupants were not universally accounted
for by existing evacuation procedures, as some were left
by colleagues (later rescued by strangers); some in WTC 1
were temporarily removed from the stairwells in order to
allow more able occupants to evacuate the building, and
others chose not to identify their mobility challenge to any
colleagues.
m Most mobility challenged individuals were able to evacuate
successfully, often with assistance from co-workers or emergency
responders, and it is not clear how many were among the 118
from below the impact floors who did not survive. It does not
appear that mobility challenged individuals were significantly
over-represented amongst the decedents.
m As many as 40 to 60 mobility challenged occupants and
their companions were found on the 12th floor of WTC 1 by
emergency responders. About 20 of these were making their
way down the stairs shortly before the building collapsed. It is
not known how many from this group survived.
4- 4 EmErgEncy managEmEnt considErations