Defensible Space
William Fries, fire marshal for the Pentagon, talks about the long process of transforming the building into a code-compliant mega-structure following the September 11 terrorist attacks
William Fries at the Pentagon. Built at the height of WWII, the facility was originally considered a temporary home for U.S. military command. (Photo: U.S. Department of Defense) |
NFPA Journal®, March/April 2013
By Fred Durso, Jr.
It may be the world’s largest office building, but the Pentagon is more analogous to a city. Located in Arlington, Virginia, and home to the headquarters of the U.S. Department of Defense, the structure includes about 3.7 million square feet (344,000 square meters) of office space. Add all the other elements of this city-under-one-roof — a bank, post office, hair salon, dental office, pharmacy, a collection of big-box stores, 43 eateries, and more — and the total swells to around 6.5 million square feet (604,000 square meters), according to the Pentagon. The building’s series of five concentric rings hold more than 23,000 military and civilian employees, with a maximum capacity of about 28,000.
It may be the world’s largest office building, but the Pentagon is more analogous to a city. Located in Arlington, Virginia, and home to the headquarters of the U.S. Department of Defense, the structure includes about 3.7 million square feet (344,000 square meters) of office space. Add all the other elements of this city-under-one-roof — a bank, post office, hair salon, dental office, pharmacy, a collection of big-box stores, 43 eateries, and more — and the total swells to around 6.5 million square feet (604,000 square meters), according to the Pentagon. The building’s series of five concentric rings hold more than 23,000 military and civilian employees, with a maximum capacity of about 28,000.
Like most cities, the Pentagon complex is subject to risks from internal and external factors, a reality that unfolded in front of a global audience on September 11, 2001. When American Airlines Flight 77 slammed into the west side of the Pentagon, killing all 59 passengers and 125 people at the Pentagon, a series of renovations was already underway to update the building’s safety features, including the installation of a sprinkler system. After assessing the damage, Pentagon officials continued their plan while emphasizing safeguards to additional threats. Part of that effort included the hiring of William Fries, formerly with the consulting firm Hughes Associates, who became fire marshal and supervising fire protection engineer for the Pentagon in 2006.
As this year’s featured presentation at NFPA’s Conference & Expo in June, Fries will highlight the fire and life safety features implemented over the past decade at the Pentagon, which celebrates its 70th anniversary this year. He talked with NFPA Journal about the terrorist attacks, the challenges of making an historic building code compliant, and how NFPA codes and standards guided this $4.5 billion project.
What kind of damage did the Pentagon sustain in the attacks on 9/11?
Flight 77 struck the west side, down at the first-floor level. It was just inside a portion that had just been renovated—the plane came in at an angle and proceeded through the building diagonally. The initial impact of the building was basically the shape of the plane, but as it crashed through the building and created explosions from the fuel tanks, the damaged area grew to about an acre, impacting the first and second floors. The significant damage structurally was on the first floor. The depth was about 270 feet (82.3 meters) into the building. The damage above that, on the third, fourth, and fifth stories, was primarily related to materials that fell — lighting fixtures, ceilings — from the impact and smoke and fire damage, versus the structural damage from the plane coming in on the lower floors.
Was the damage affected in any way by the renovations that were already going on?
If there was a blessing at all that day, it was because of exactly that. The renovation of the Pentagon started in the mid 1990s and had basically just been completed through [a section located at] the edge of where the plane hit. We were still in the process of moving people in, so the occupant load where it hit was lighter than it would have been if it were fully occupied. We’d already started vacating the area next to it, so what the plane continued to crash into was vacant space. We still lost a significant number of people in the building, but we were lucky in that we had fewer people in there.
What initially prompted these renovations?
The building was completed in 1943. By the mid 1990s, the building’s infrastructure had deteriorated beyond repair. Plus, the building was built during the time when asbestos-containing materials were prevalent. There was also no real infrastructure for information technology. We also have a building that is certainly subject to an attack, by the nature of what it represents. Some people in this world look at our building with great comfort and some with great disdain. That being the case, we have a level of risk that is greater than most buildings. Knowing what we’ve done from a fire and life safety standpoint, I’m more comfortable working in this building now than before the renovations.
What are those fire and life safety upgrades?
Part of the renovation was to upgrade to current codes and standards. We were considering it basically a new building, or as much as you can make it new. We’re also a historical structure. The fire alarm system has been fully upgraded to a system compliant with NFPA 72®, National Fire Alarm and Signaling Code. We are still in the process of upgrading portions of the mass notification aspect. We now have a fully sprinklered building, new standpipe systems, and compliance with NFPA 101®, Life Safety Code®. We’ve increased the code requirements for passive fire protection. For instance, storage rooms, closets, and areas of that sort, where there isn’t a requirement for fire barrier separation, we’ve upgraded them to one- or two-hour fire barriers based on size.
What impact did 9/11 have on the renovations?
After 9/11, we took a step back and said, “What lessons were learned?” During the attack, we had a major fuel fire in the building, something you typically wouldn’t find in an office structure. We found that it may be a reasonable scenario that we had to consider. What extra steps do we need to make sure people can see their way out of a building? Since smoke from burning aircraft fuel banks down to the ground very rapidly, we installed low-level photoluminescent exit signs, including everything from arrows directing people to the nearest exits to the labeling of exits at the floor level. We also had to rethink our sprinkler protection for a variety of reasons after 9/11. If you follow strict interpretation of NFPA 13, Installation of Sprinkler Systems, the Pentagon is a business occupancy and it would follow requirements for “light hazard” occupancies. We upgraded to “ordinary hazard” because of the possibility of greater challenges.
Did the fire sprinklers that were installed during this project impact fire spread on 9/11?
The plane hit right at the edge of the renovated versus non-renovated section. If you look at photographs, to the right of the building, you’ll see the fire didn’t progress very much past the impact because it was held in place by sprinklers, even though they were severely damaged in the attack.
What were the challenges of applying modern codes and standards to a historic structure?
That’s always difficult and challenging. You want to preserve its beauty, but you need to provide fire and life safety aspects. For instance, floors are connected by large, steep ramps. They were put there when the building was originally built during World War II. The Pentagon was built to provide assistance to the war’s mission at the time, but they thought there wouldn’t be a need for such a building after the war — there was talk of turning it into a records-keeping building or a rehabilitation hospital. Also, because of the war effort, they were preserving metals, which is why they didn’t want to construct many elevators. So the ramps were appropriate. We made sure we had a sufficient number of stairwells as part of the renovations to accommodate all of the evacuation needs without using the ramps as an evacuation pathway. When you look at them, they still look beautiful and open and just as they have always been, but they haven’t impacted us from a fire or life safety standpoint.
Have all of the upgrades been completed?
We are still working on areas that are referred to as “No Man’s Land” — these are unique spaces in the building that were outside of the project. We have been allocated budget funds to address those. They are smaller in scale — maybe a stairwell that was in a different portion of the building that only goes two floors. We’re upgrading those to fully meet provisions in NFPA 101.
Was there any political pushback on this project?
We spent millions of dollars on fire and life safety features, and we have excellent results because of that. Obviously we had good political support to do it right. In a government environment, you have to fight for funds for anything. With the money we were given, we had to believe we had the support we needed to get the job done, because we got the job done.
How have these improvements enhanced your job?
The life of a fire marshal, of a fire protection engineer, is always easier in a code-compliant setting. It’s still very challenging. There’s never a dull day — there’s never repetition with the work. We have everything a city has under one huge roof. Each day something’s going on that requires our attention, either new construction, processing of a permit, an inspection, a fire. You name it, we deal with it. We also have to constantly deal with creative ways to solve problems. We’ve developed a wonderful working relationship with our security team to make sure the thousands of occupants remain safe. Working together, we have solutions that meet life safety and security concerns. Working individually, that wouldn’t happen.
Interview condensed and edited by NFPA Journal staff writer Fred Durso, Jr.