Rob Jackson, P.E.
Design and Construction Management Division
City and County of Denver, Colorado
Our world is in many ways a potentially vulnerable place, especially when the power of natural hazards or a diabolical bombing results in the tragedy of a building collapse. Such disasters present challenges to our communities to protect and preserve human life and safety. One of the first goals in such an event is to find and rescue trapped victims. The primary group providing these indispensable services is the Urban Search and Rescue (USAR) team.
Emergency response to a potential disaster involves many participants, often with multiple roles and sometimes overlapping responsibilities. The roles of USAR members are specific to the task of locating, rescuing and treating entrapped victims of the structural collapse of buildings, viaducts, bridges or similar structures. Public works employees may provide valuable skills and experience in support of or as a part of USAR teams. This support may be to either the Federal Emergency Management Agency (FEMA) USAR Task Forces or to local fire department teams performing USAR tasks in the absence of a federal deployment. Coordination and initiative at the local level is very important in developing these types of local organizations.
The National Urban Search and Rescue Response System, established by FEMA in 1989, provides for local emergency services personnel to be integrated into disaster response Task Forces for federal deployment. Sponsored by State and local government emergency response organizations, the civilian Task Forces are intended to be self-sufficient. Currently, there are 28 FEMA USAR Task Forces in 19 states throughout the continental United States.
Any Task Force can be deployed by FEMA to a major disaster. Two Task Forces have also responded to several international disasters. A Task Force is comprised of 62 specialists, organized into 31 positions and divided into four major functional elements: Search, Rescue, Technical and Medical. Most of the Task Force is made up of local fire department and emergency services personnel who are experienced and trained in collapsed structure search and rescue operations. Task Force members include structural engineers and specialists in the areas of hazardous materials, heavy rigging, search (including highly trained search dogs), logistics, rescue and medicine. By design, there are two Task Force members assigned to each position for the rotation and relief of personnel. This allows for round-the-clock Task Force operations.
Disasters and emergencies vary widely in scope, degree of devastation, and threat to human life. In a structural collapse, large numbers of people may require rescue and medical care. Because the mortality rate among trapped victims rises dramatically after 72 hours, USAR must be initiated without delay. In the course of response, rescue personnel may encounter extensive damage to the local infrastructure as well as environmental safety and health hazards. Following an earthquake, aftershocks and secondary events may compound problems. Weather conditions may pose additional hazards. In some circumstances, rescue personnel may be at risk from terrorism, civil disorder, or crime.
Earlier this year, the City of Denver Fire Department, along with Turner Construction, hosted a three-day search and rescue exercise during the demolition of Denver's McNichols Sports Arena. The partially demolished structure served as a real-life training ground for USAR Task Forces and firefighters from 30 agencies in one of the largest exercises in history. Although there were no real victims, the risks to the rescuers were real, since elements of the structure hung precariously and rubble was present throughout the facility.
Structural engineers from Denver Public Works, Denver Fire and the Building Inspection Division provided a "safety officer" role at the site. There were no injuries to event participants. Other public works personnel assisted with traffic control and utility evaluation. Plans of the facility were obtained and scanned into electronic files. The drawings were then available for review by Denver volunteers as well as the USAR Task Forces and the other agencies involved in the training. The engineers reviewed hazardous conditions, shoring construction and assisted in planning for safe routes and additional demolition where necessary to ensure safety.
It is very important to obtain good building plans prior to an event. These drawings can be used for the rescue personnel as well as by the engineers in evaluating the structure. Nonetheless, the drawings may still need verification in the field. A partially collapsed building gives plenty of information to a structural engineer. For example, when there are questions as to the structural properties of a concrete cross section, a failed member may be readily inspected for the size and number of rebar to assist in the evaluation of similar members. The decision as to whether to shore or demolish precarious elements of the building must be made quickly while obtaining as much information as possible.
The process of review of both the drawings and similar field conditions at McNichols resulted in a safer exercise. We had one condition where the drawings did not match the observed conditions in the demolished areas. This required additional shoring of one member during the demolition of another. It also allowed us to better sequence the cutting of the reinforcing steel for increased safety.
The emergency management cycle includes four phases: mitigation, preparedness, response and recovery. Public works has many roles in these phases, response included. These will depend on the nature of the disaster and what functions are included in the organizational structure of the local public works department. The real scope of public works involvement may extend beyond the organizational boundaries of the traditional local public works organization. Public works is one of the four "First Responders." The others are fire, law enforcement, and medical.
In the Incident Command System (ICS), public works provides the Incident Commander for response to snow storms or floods. Earthquakes, high winds, terrorist activities and other events that may result in structural collapse usually require the fire department to provide the Incident Commander. Public works then provides logistical support and technical advice. Public works employees may also serve as volunteers on a USAR Task Force or in support of a Task Force, which is called upon to respond to a local disaster. Structural engineers, riggers and those with hazardous materials backgrounds are needed. The presence of well-trained USAR Task Forces is an important preparedness component in mitigating the loss of human life and facilitating response during a disaster.
For more information, please contact Rob Jackson at 720-913-8816 or at firstname.lastname@example.org.