In the aftermath of the terrorist attacks against 

our nation on September 11, 2001, thousands of

America’s workers responded by joining hands to

recover the remains of those who had been lost 

and to reclaim the ground where the twin towers of 

the World Trade Center once stood. Working around

the clock, under unimaginably dangerous conditions,

they endured and prevailed. 

Out of the chaos emerged a strong and effective 

public-private partnership that ensured protection for

the workers at the site. OSHA joined forces with the

City of New York, construction contractors, labor

unions, and all levels of government in a pledge to

recover the site with no further loss of life. 

The partners achieved their goal. On May 30, 2002,

when the recovery was complete, not another life had

been lost, and illness and injury rates were far below

the national average for the industries involved in 

the recovery.

John L. Henshaw

Assistant Secretary of Labor

for Occupational Safety and Health

U.S. Department of Labor 
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THE GREEN LINE

A green line, painted around the perimeter of

the World Trade Center (WTC) site, defined

the recovery area. Within and around this

boundary, OSHA worked for 10 months with

its partners in safety and health to protect 

the well-being of workers on the site. Within

that space, no workers lost their lives in the 

recovery effort that followed the tragedy of

September 11, 2001.

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OSHA’S ROLE

OSHA’s strategy at the WTC was to pursue 

collaboration while suspending enforcement and

providing consultation, guidance, and technical

assistance with a sound safety and health plan.

Our goal from the start was protection, not citation.

From the very beginning, OSHA knew that the

recovery of the WTC site would be no ordinary

demolition project. At the center stood a mountain

—all that remained of two skyscrapers that once

soared 110 stories high and defined the New York

City skyline for decades. 

OSHA had addressed many of these hazards

before, but not on such a vast scale. No one

could deal with the catastrophe alone. No 

one group had all of the answers, equipment, 

experience—let alone the personnel—to protect

the safety and health of workers at the site. How

would they accomplish that goal? The answer 

lay in partnership. 

Informal collaboration of initial responders had

begun early. But soon, representatives from every

group involved in the recovery effort would formally

agree to join in a team effort to protect the safety

and health of workers at the disaster site.

Secretary of Labor Elaine Chao led the signing of

the formal partnership. Speaking at the ceremony

in New York City on November 20, 2001, Chao

declared, “American workers—from city, state, and

federal government agencies, trade associations,

contractors, and labor organizations—formed a

partnership to reclaim this site and recover our 

fellow citizens. They’ve done this with pride, dignity,

talent, hard work, and dogged determination.” 

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PARTNERSHIPS

Signatories to the World Trade Center Emergency

Project Partnership Agreement:

• AMEC Construction Management, Inc.

• Bovis Lend Lease LMB, Inc.

• Building and Construction Trades Council 

of Greater New York (BCTC)

• Building Trades Employers’ Association (BTEA)

• Contractors Association of Greater New York 

(CAGNY)

• Fire Department of New York (FDNY)

• General Contractors Association (GCA)

• New York City Department of Design 

and Construction (DDC) 

• Occupational Safety and Health Administration 

(OSHA)

• Tully Construction Company, Inc.

• Turner/Plaza Construction Joint Venture

IDENTIFYING RISKS AND HAZARDS

Many hazards threatened the safety and health of

site workers. They included risks caused by

cranes lifting beams of unknown weight and

improperly handled compressed gas cylinders that

might explode, as well as threats posed by falls

and falling objects, hot steel, confined spaces,

Freon, and much more. 

A list of the most dangerous risks facing the WTC

recovery workers follows:

THE WORKERS

A flood of workers soon poured onto the site. 

Here is a partial list:

• Asbestos Workers 

• Boilermakers

• Carpenters

• Cement Masons

• Construction Managers 

• Electricians

• Emergency Medical Technicians 

• EPA employees

• FEMA workers

• Fire Fighters

• Heavy Equipment Operators

• Insulation Workers

• Ironworkers

• Laborers

• Machinists

• Medical Doctors and Coroners

• National Guard

• NIOSH employees

• Office Cleaners

• OSHA staff

• Paramedics 

• Plumbers and Pipefitters

• Police Officers

• Psychologists

• Red Cross workers

• Registered Nurses

• Rescue Workers

• Riggers

• Safety and Health Professionals

• Sheet Metal Workers

• Steamfitters

• Steelworkers

• Structural Engineers

• Truckers and Teamsters

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Identifying Risks and Hazards:

CRANES

More than 30 cranes, including some of the

largest in the world, were at work in uncomfortably

close quarters inside the green line. In what has

been described as an intricate balance of motion

and timing, the cranes lifted loads of twisted steel

and compacted rubble in an environment fraught

with the potential for accidents. High winds, rain,

unstable ground, and uncertain loads added to

this dangerous mix. 

OSHA saw the need for special focus to address

the growing concern over crane operations. 

The agency consulted with various partners 

and then launched a Joint Crane Inspection 

Task Force. Composed of representatives from 

OSHA, contractors, and the International Union of

Operating Engineers (IUOE), the task force spent

two days inspecting 17 cranes inside the green

line. They found numerous serious hazards on

more than half the cranes. Most of the hazards

involved crane set-up, rigging, and hoisting 

practices. Crane set-up continued to be an issue

because the giant steel towers often rested on

unstable platforms as fires burning deep in the

pile caused the cranes to shift. The task force

identified hoisting personnel with man-baskets 

as the most serious concern. For example, in 

the early days of the recovery, workers modified

garbage dumpsters with welding torches, then

hooked them to cranes to lower workers into 

the pile. 

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10 11

The crane safety effort yielded further success

when inspection teams learned that faulty 

equipment might be put back into service. The

task force inspected 222 pieces of rigging and

found 81 deficient in one sector of the site.

Employers in the other three sectors soon began

to remove suspect rigging before the task force

arrived. OSHA reported 151 safety interventions

involving crane operations, about 21 percent of 

all hazard corrections made inside the green line.

The number of problems dropped consistently

after organization of the task force.
Identifying Risks and Hazards:

HEAVY EQUIPMENT 

The combination of rescue workers performing

recovery operations side by side with demolition

workers using heavy equipment in tight quarters

and under great emotional stress posed unique

challenges. Ordinarily, rescue workers are not

present when machines such as excavators,

grapplers, and debris trucks are operating. This

was not the case here. OSHA consulted with 

construction personnel, labor representatives, and

emergency responders to find a simple solution

that made a big difference. The wearing of brightly

colored reflective vests made the workers visible

to the equipment operators and reduced the

potential for serious injury or even death. A

mandatory distance between rescue workers and

heavy equipment provided additional protection.

The sheer size and instability of the debris pile

posed further complications. The mountain of

mangled debris rose six stories above ground 

and descended seven below; voids within caused

ever-changing shifts and constant hazards. With

heavy equipment operating on such unstable 

surfaces, there was special cause for concern.

Yanking twisted steel from one spot could undermine another and send an operator into a hole

several stories deep. Safety officials worried daily

about the potential for such falls. They kept a

close eye on the number of workers operating

heavy equipment and on their proximity to others

working on the pile. There were many “near misses,” including an unattended crane that fell 30 feet

when the platform of rubble on which it sat gave

way. Constant vigilance—and in a few cases, fate

and good luck—averted near disaster.

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Identifying Risks and Hazards:

FALLS AND FALLING OBJECTS 

Falls are routinely the most common cause of

workplace injuries in the United States. At the

WTC site, workers often had to operate several

stories above ground and in very uncertain 

environments. The odds for disaster were great.

OSHA set up special training in fall prevention

methods and technology for the workers and their

supervisors to help them reduce or eliminate 

the risks. 

Meanwhile, the New York City Department of

Design and Construction (DDC) worked hard to

reduce the hazards of falling debris and structural

instability posed by the surrounding buildings.

They brought in contractors to secure the premises,

install vertical netting, and erect sidewalk sheds

and canopies to further protect the workers.

OSHA safety monitors and other safety 

professionals constantly roved the site, identifying

and addressing hazards. Safety personnel often

interrupted an activity to ask that workers tie-off or

find a safer way to proceed. They also checked

scaffolding, performed job risk analysis, and made

sure workers understood safety rules for aerial

lifts. On one occasion, a load of debris fell directly

on a spot where firefighters had stood 

only moments earlier. 

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Identifying Risks and Hazards:

EXPLOSIONS

Numerous compressed gas cylinders used 

by burners to cut steel beams and rebar were 

scattered around the site. These cylinders included

oxygen and acetylene tanks, both extremely 

hazardous if not handled properly. In the early

days of the rescue effort, these tanks were largely

unsecured, lying haphazardly on the ground. To

reduce this hazard, OSHA joined forces with the

Fire Department of New York to patrol the site and

ensure that contractors followed proper storage

and handling procedures.

The potential for explosions was always present

at the site. In one case, a fuel tank with tens of

thousands of gallons of diesel fuel was buried

seven stories below ground. With smoldering

fires, a rupture could have been disastrous. Once

workers located the tank, it was safely emptied,

and the fuel was removed from the site. 

The parking garage under the WTC held nearly

2,000 automobiles, each tank holding an estimated

five gallons of gasoline. When recovery workers

reached the cars, they found that some had

exploded and burned while others remained intact. 

Building 6, the former site of OSHA’s Manhattan

Area Office, housed many federal agencies,

including the U.S. Customs Service. More than

1.2 million rounds of their ammunition, plus explosives and weapons, were stored in a third-floor

vault to support their firing range. OSHA worked

closely with other government agencies to determine what protective measures were necessary

so that the ammunition could be safely removed.

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Identifying Risks and Hazards:

HOT STEEL

Even as the steel cooled, there was concern 

that the girders had become so hot that they 

could crumble when lifted by overhead cranes. 

As a result, additional safeguards were put in

place to limit the dangers associated with lifting

the damaged steel and to protect the workers 

in the vicinity. 

Another danger involved the high temperature of

twisted steel pulled from the rubble. Underground

fires burned at temperatures up to 2,000 degrees.

As the huge cranes pulled steel beams from the

pile, safety experts worried about the effects of 

the extreme heat on the crane rigging and the

hazards of contact with the hot steel. And they

were concerned that applying water to cool the

steel could cause a steam explosion that would

propel nearby objects with deadly force. Special

expertise was needed. OSHA called in structural

engineers from its national office to assess the 

situation. They recommended a special handling

procedure, including the use of specialized rigging

and instruments to reduce the hazards.

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Identifying Risks and Hazards:

FREON

Huge underground tanks held more than 200,000

pounds of Freon stored to cool the seven buildings

of the WTC complex. This had been the largest

air-conditioning system in the country. 

OSHA personnel were concerned that workers

entering areas below grade could be exposed to

Freon gas, a known, heavier-than-air, invisible

killer. After a leaking tank was discovered, agency

staff and the site construction manager carried out

special sampling for months until all the tanks

were uncovered and safely removed.

Identifying Risks and Hazards:

CONFINED SPACE

OSHA has investigated hundreds of cases of 

carbon monoxide poisoning across the country.

Often this hazard is not immediately apparent,

and what may seem to be an open-air atmosphere

is really a more deadly confined space. Rescue

and recovery workers entered collapsed buildings

where the atmospheric hazards from fire and 

toxic fumes could have been fatal. 

Besides the usual hazards in confined spaces, the

site conditions at the WTC posed the additional

risk of structural instability. The DDC designated

certain areas for special attention. For example, 

a sudden and catastrophic release of Freon could

overcome workers performing demolition and

recovery operations inside collapsed buildings.

OSHA helped DDC establish safe entry protocols

for these areas.

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EMPLOYER EMERGENCY

EVACUATION PLANS

OSHA suggests that workplaces review and 

practice their plans with an emphasis on the 

following:

• Finding alternate exits. 

• Accounting for all employees.

• Designating alternate rendezvous points. 

• Developing procedures for the disabled.

EMERGENCY RESPONSE

PARTNERSHIPS

Emergency response partnerships, with clear

lines of authority for all functions at a site and with

special emphasis on safety and health, should be

created immediately to promote effective disaster

site management. 

In addition, OSHA recommends the following as

key elements for emergency response partnerships to consider in planning for disasters:

EMERGENCY TRAINING

For first responders and federal law enforcement

agencies:

• Develop outreach and training materials.

• Address safety and health issues related to 

incidents involving terrorism and weapons of 

mass destruction.

LOOKING BACK

OSHA’s commitment to the WTC recovery

involved more than 1,000 agency employees

working 24 hours a day, seven days a week,

alongside other federal, state and local agencies

to ensure the safety and health of workers at the

site. At the height of this effort, 75 OSHA staff

worked the site each day and OSHA personnel

provided more than 15,000 work shifts. 

OSHA 

• Collected more than 6,500 air and bulk 

samples to test for asbestos, lead, other 

heavy metals, silica, and various organic and 

inorganic compounds.

• Conducted more than 24,000 evaluations of 

worker exposure. 

• Conducted sampling around-the-clock. 

• Distributed more than 131,000 respirators, 

11,000 hard hats, 13,000 safety glasses and 

goggles, and more than 21,000 pairs of 

protective gloves.

• Identified more than 9,000 hazards.

After September 11, 2001, not one life was lost 

inside the green line during the recovery effort. 

LESSONS LEARNED

OSHA learned a great deal at the WTC site, 

lessons that can help the agency improve its 

own emergency preparedness while also helping

employers prepare for emergency response. 

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FIT TESTING

Emergency responders at all levels of government

should be routinely fit-tested for respirators.

COMMUNICATION

• Improve channels of communication with other 

local, state, and federal agencies.

• Improve emergency communication capability.

TRANSPORTATION

• Coordinate access to military transportation.

• Plan for emergency transportation. 

THE FUTURE

OSHA continues to work with other federal 

agencies across government to improve 

cooperation and collaboration in the event that 

a coordinated response on such a massive 

scale is ever needed again. If the need arises, 

OSHA will be ready.

OUTREACH 

Emergency responders, managers, and incident

commanders should:

• Plan for emergency responses.

• Ensure early and complete implementation of 

the incident command system (ICS) and/or 

Unified Command at all incidents. 

• Designate safety officers with no collateral 

duties and sufficient authority.

• Conduct comprehensive site risk assessments.

• Make safety and health protections a priority.

• Protect employees from job hazards.

• Install proper shoring.

• Pay attention to material handling equipment 

and rigging.

• Monitor worksites for health risks.

• Consider environmental conditions, stress, 

and fatigue. 

• Control access to the site. 

• Manage volunteers effectively.

• Manage donations, especially unsolicited 

in-kind goods. 

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OSHA 3193-11-03

Photography credit:

Inside front cover top & bottom, Andrea Booher/FEMA; 

Page 2 top, Shawn Moore/DOL; bottom, Andrea Booher/FEMA;

Page 4 top, Andrea Booher/FEMA;

Page 8, Andrea Booher/FEMA; 

Page 11 top & bottom, Andrea Booher/FEMA; 

Page 12 top & bottom, Michael Rieger/FEMA; 

Page 15 top & bottom, Andrea Booher/FEMA; 

Page 16 top & bottom, Andrea Booher/FEMA; 

Page 19 top, Shawn Moore/DOL; bottom, Andrea Booher/FEMA; 

Page 20 top & bottom, Gil Gillen/OSHA.