It is a new documentary. It almost has a "docu-drama" feel to it.
From Discovery.com:
Most civilians recall simply being taught to await the instructions that would be provided at the time of an emergency. Civilians were not informed that rooftop evacuations were not part of the evacuation plan, or that doors to the roof were kept locked.
The Port Authority acknowledges that it had no protocol for rescuing people trapped above a fire in the towers.
The World Trade Center lacked any plan for evacuation of civilians on upper floors in the event that all stairwells were impassable below.
Between 16,400 and 18,800 civilians were in the World Trade Center complex at 8:46 a.m. on Sept. 11, 2001.
Approximately 87 percent of the estimated 17,400 occupants of the towers, and 99 percent of those located below the impact floors, evacuated successfully.
A principal factor limiting the loss of life was that the buildings were one-third to one-half occupied at the time of the attacks. The National Institute of Standards and Technology (NIST) estimated that if the towers had been fully occupied with 20,000 occupants each, it would have taken just over three hours to evacuate the buildings and about 14,000 people might have perished because the stairwell capacity would not have been sufficient to evacuate that many people in the available time.