Post-Construction Fires Prior to September 11, 2001. Federal Building and Fire Safety Investigation of the World Trade Center Disaster.
Post-Construction Fires Prior to September 11, 2001.
Federal Building and Fire Safety Investigation of the
World Trade Center Disaster.
Kuligowski, E. D.; Evans, D. D.; Peacock, R. D.
NIST NCSTAR 1-4A; 140 p. September 2005.
World Trade Center; high rise buildings; building
collapse; disasters; fire safety; fire investigations;
terrorists; terrorism; construction; fire departments;
codes; fire detection fire suppression; smoke purge
Fires occurred in World Trade Center (WTC) I, 2, and 7
prior to September 11, 200 1. This report documents the
facts of significant fires in the buildings after first
occupancy as they relate to the performance of the
automatic sprinkler, manual suppression, fire detection,
and smoke purge systems. The ultimate goal of this
review was to identify from New York City Fire
Department (FDNY) records significant but not well-known
fires for further study. From the information contained
in FDNY fire reports and fire investigation records
provided to the National Institute of Standards and
Technology (NIST), 47 fires occurred in WTC 1, 2, and 7
that were of sufficient size and duration to activate
multiple sprinklers or were estimated by NIST to be
capable of doing so, over the time period the buildings
were occupied. This total does not include the major
1975 office fire in WTC 1 or the 1993 bombing. The
records indicate that in areas protected by automatic
sprinklers, no fire activated more than three
sprinklers. Three sprinklers would provide coverage for
a floor area of approximately 675 ft2 (63 m2). This area
is much smaller than the 9,000 ft2 (800 m2 damaged by
the 1975 fire in an office space unprotected with
automatic sprinklers. Many of the fires that occurred
were recorded as suspicious or unknown in cause,
occurred during off peak work hours, and involved
materials such as trash or paper-based supplies. In
cases where sprinklers were activated, the FDNY records
indicated that the sprinklers either extinguished the
fire completely or aided in controlling the spread.