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Weapons of Mass Destruction Threat Assessments and its Impact on Full High-Rise Building Evacuations
Presented at the Urban Hazards II Forum - "Homeland Security after 9/11" -
John Jay College, NYC, January 23-24, 2003

Presented by Jack J. Murphy, Vice-Chairman / Executive Board
Fire Safety Directors Association of Greater New York

Over the years, we have learned to navigate a high-rise building fire evacuation by vacating to several floors below the incident and staging there for further evacuation, if necessary. The high-rise building means of egress have been designed around this half-hearted "defend-in-place" practice. I advocate this because not all high-rise structures are fully sprinkled nor segregated into floor fire compartments. And the fire loads on many floors far exceed the capacity of fire department hose streams. If not for the beliefs of "defend-in-place", the engineers and architects would have designed the egress means accordingly and the objective would more than likely resemble our Madison Square Garden stair and ramp egress widths and the street level exit discharge components. Even the foremost of all egress practices, the National Fire Protection Association, Life Safety Code 101 has never thought it necessary to deploy a full high-rise building. Collectively we have all failed to meet the riggers of a full high-rise building evacuation.

While we still have not fully conquered all the high-rise fire safety requirements, we are as a group thrown together with today's Weapons of Mass Destruction [WMD] crisis to augment rapid deployment procedures for evacuating all occupants with a limited capability of the high-rise building means of egress.

So how do we safely and pragmatically go about accomplishing this feat?

For today, let's just discuss some necessary threat assessments for an internal chemical incident and how it may affect a full building evacuation:

I. A Reconnaissance of Building Systems is Essential for;

Some key systems are HVAC, Elevators and Communications

HVAC systems;

  • Where are the air in-takes and is there a vulnerability here?
  • How many HVAC zones and what areas do they cover?
  • If a contaminant is present, can the smoke management system and/or building management system be used to purge the agent? After normal working hours is the building management system remotely controlled off site?

    Some building natural air supply advantage points;
  • If present, do building setbacks have the capability to temporally stage occupants for fresh air?
  • Are windows immediately operable and if not are window keys readily available?
  • What if the building is totally sealed?

Elevator banks;

  • What floors do the elevator banks serve?
  • Are the various elevator banks present for low-rise, mid-rise and high-rise levels?
  • Is a sky lobby present and at what floor levels?
  • Do blind shafts exist and what floors do they by-pass?
  • Do any of the elevator banks cross over into another HVAC zone?

Communications Capability - Fire Alarm System [FAS]
The high-rise building fire alarm voice communications system is the most critical equipment for an effective evacuation, yet it is very vulnerable in many present high-rise structures because the location of the Fire Command Center [FCC] opens onto the lobby/atrium area. The potential loss of the FAS voice communications system during a lobby chemical attack could render the communications system inaccessible, thus negating voice communications onto all floors.

  • Is there a redundant and remote emergency voice communications system?
  • Do the occupants have confidence in the voice that they hear?
  • Are the announcements clear and the directions understandable to the floor occupants?
    1. Do we use for Fire -"Code Red" that signifies a partial evacuation?
    2. Do we use for Emergencies other than Fire - "Code Black" signifying a full building evacuation, like a chemical incident?
  • For WMD threats do we provide specific evacuation information and direct the occupants to the least threatened area of the building?
  • When the lobby is not affected, have we assembled at the Fire Command Center a "Chemical Threat Management Team" that consists of the building Fire Safety Director, a Security Supervisor and the HVAC engineer, to assist in the mitigation?

II. Evacuation Concerns for a Chemical Incident:


  • What types of stair towers are present to mitigate an evacuation?
    1. Pressurization with a fan capability
    2. A fire tower with an enclosed vestibule off each floor that is open to the atmosphere prior to entering into the stair tower itself.
    3. Or just an enclosed stair with no air movement.
  • What stairs discharge directly onto the street?
  • Are there any access stairs between floors?
  • What are the re-entry floor levels? And how do we release the secured stair tower doors, if an automatic fire alarm device does not release the doors?

Use of elevators for rapid evacuation, especially for disabled people, may depend on the location of the chemical release. The potential effect of elevator movement may cause a drawing of the chemical agent up the elevator shaft.

III. Occupant training for WMD;

  • Evacuation phases;
    1. Training for floor evacuation teams [FET]
    2. Full building evacuation drill for FET's
    3. Floor evacuation drill for all occupants
    4. Full building evacuation
  • "Buddy System" for people with a disability
  • Exterior points of assembly

IV. High-Rise Vulnerability Enhancements;

  • Increase stair widths to a minimum of 55 inches between the handrails. The new design of # 7 WTC has incorporated a minimum width of 66 inches. While it is difficult to retrofit stair widths in existing buildings, it does not preclude the fact that we can enhance a rapid evacuation by making a Phase IV elevator bank that is water and smoke proof.
  • For easier stair identification, emergency lighting, photo-luminous signage and a sound alert system should all be incorporated.
  • Increase exit discharge at the grade level, particularly if only 1 of the 2 stair towers are available during an emergency incident.
  • Enclose the lobby Fire Command Center with a 'bunker type' shielded protection. Relocate it to the street side of the building and provide a fortified exterior access door for the fire department.
  • Provide a redundant type emergency communications system.
  • Assign a dedicated Fire Safety Director whose sole function is life safety for the building occupants. We have more people in many high-rise buildings than communities across this country, yet we entrust numerous high-rise buildings to a person who has no experience with emergency incidents and then we ask them to make split-second life safety decisions for a multitude of potential evacuation strategies.

To apply pragmatic life safety means to current Weapons of Mass Destruction threat issues, senior management whether corporate or real estate management, now more than ever, must coordinate an inclusion of both life safety and security. Together we can collectively raise the bar on ensuring the building occupants that a due-diligence is being preformed prior to the arrival of any First Responder.


(Presented at the Urban Hazards II Forum - "Homeland Security after 9/11" - John Jay College, NYC, January 23-24, 2003) © Copyright 2003 Jack Murphy.

Sally Regenhard,

P. O. Box 70
Woodlawn Station
Bronx, NY 10470

Monica Gabrielle,

P. O. Box 70
Woodlawn Station
Bronx, NY 10470