Pruitt-Igoe and the failure of the modern housing projects

Gather round, my children, and I'll tell you the story of Pruitt-Igoe, a housing project that was meant to be the post-war hope of the future and ended up being a sorry mess.

The Pruitt-Igoe public housing complex was designed by Minoru Yamasaki, a Japanese architect who followed the International Style (what most of us think of as "modern"), for the city of St. Louis. Post-WWII, St. Louis the city had been deserted by anyone with any money for the suburbs. The city decided to demolish a large swath of dilapidated houses and small, run-down apartment complexes and put up instead Le Corbusier's wet dream.

The complex was designed in the early 1950s, and after a round or two of value engineering (where you change the design in order to decrease the cost of a project), construction was completed in 1955. Over 50 acres were cleared for the 33 buildings of the complex. The buildings were originally separated into two groups, the Pruitt complex and the Igoe complex; one would hold blacks and any other minorities, and the other would hold whites. The complexes were integrated in the late 1950s. Upon its completion, the world's architecture journals praised it as a beautiful example of International Style housing, which many architects of the time believed was just the way to alleviate and even end poverty and to cure society's ills. Some residents, upon first moving in, said it looked like a dream come true.

But it wasn't long until the complex looked like this:

Remember that value engineering I mentioned earlier? First of all, Yamasaki's firm proposed a mix of varying heights and densities of buildings--low rise, high rise, and walk-ups (not more than three stories)--but that plan was nixed and all buildings were set at eleven stories each in order to economize each building's construction. Some politicians attributed the high cost estimates to having to pay union wages to the construction crews. Regardless, money had to be saved somehow, and changing the size and shape of the buildings wasn't the only way. In order to get more people into smaller building footprints, the units were way too small and had inadequate kitchens and plumbing fixtures. Even worse were that the elevators only stopped on three of the eleven floors--it costs a lot of money to stop an elevator on a floor, so by stopping it on the first, fourth, seventh, and tenth, you save a lot of cash, right?

What they saved in up-front construction cost, they lost in the long run. Too many people from different neighborhoods in substandard conditions made for a lot of tension amongst the residents. Thugs and thieves waited in the stairwells for people returning from their jobs with paychecks and the mailboxes with their monthly assistance checks as they climbed up to their floors where the elevators didn't stop.

By the late 1960s, only one of the buildings had any residents in it at all. Estimates vary on maximum occupancy, but they range from 33% to 60% full at its fullest. The first of the buildings was imploded in 1972, and the last imploded in 1976. In 21 years, the critically-acclaimed housing complex was no more.

So what happened? I don't think the fact that it was a "modern" building was the problem. My research on designing homeless shelters (that was my thesis, bitches) as well as my experience in healthcare architecture has shown me that if you don't give people nice things, they don't care about what's around them and won't take care of it. Put poor people who know they're poor in cheap-ass-looking public housing and don't even give them adequate space and for the love of Philip Johnson, you don't even have the elevator stop on each floor...well, you've made it pretty clear that you don't think very highly of these folks. And they will behave accordingly and treat their building that way.

It's also a matter of scale. The psychological concept of crowding has shown in animal studies and to a less-controlled extent in people that if you put too many of any mammalian species in a given area, they react poorly and engage in destructive behaviors. Furthermore, it's worth noting that a nearby public housing complex that had fewer units per building had much less vandalism, and its residents were much more careful about taking care of their gronds and keeping them clean. Studies have shown (and of course I can't put my hands on them right now, but I distinctly recall this) that people are more likely to help out when there's fewer of them present. One study on this concept found that if there are ten people in a room, and they hear someone fall in the next room and cry out, the "oh help!" person is not very likely to get help from any of those people, but they're much more likely to get help if there are only one or two people in that other room. So, with Pruitt-Igoe, if you put 20 units on a floor, they tend not to take care of their public areas (halls, courtyards, etc.) as much as they would if there were three or four units on that floor. In my eyes and experience, the failure of Pruitt-Igoe was less of an architectural aesthetic failure and more of a planning, policy, and psychology/sociology failure.

By the way, Pruitt-Igoe was not the only notable piece of architecture that Minoru Yamasaki designed. Know what else he did?

I bet you do know.

Edited 12/9/2011: I appreciate the continued feedback on this post, and I'm aware that evidence regarding the architectural intentions of Pruitt-Igoe's architect and the planners have recently been made clearer in a variety of books and articles in the past several years. More recently, a documentary title The Pruitt-Igoe Myth sought not only to delve into the socioeconomic issues involved in Pruitt-Igoe's creation and demise but also to understand the architectural and planning issues and decisions made regarding the project. As better information and research on this topic is produced by others who have the time and ability to do so, I urge readers to seek out those resources and will close this particular post for receiving comments. Glad to know that this topic still provides lively discussion in the public sphere, and hopefully it will continue to do so in the spirit of improving the public realm's aesthetic as well as how we care for those less fortunate than us.

Designing for Disaster

Wandering Author asked in the last round of comments:

"It was your mention of fireproofing to keep the columns from deforming in a fire that got me thinking. I'm sure you've heard some of the questions surrounding the three building collapses on 9/11. Do you have an opinion you don't mind airing?"

Well, WA, I have some knowledge to drop here indeed. First, I will acknowledge the existence of the conspiracy theory that the World Trade Center Towers were "helped" down with strategically-placed detonation charges placed the weekend before 9/11 by a demolition crew partially owned by a member of the Bush family so that the U.S. could attck the Middle East. However, since good intel on this is unavailable to me and the rest of the world, I can only comment on the evidence we do have, which is that the Towers fell due to physics.


Now, let me begin with commentary provided by WAD's resident aviation expert, former Army helicopter mechanic and almost-chopper pilot, Sgt. J.P. Sarge, now CAD Manager at Design Associates:

At the time the buildings were erected, no one conceived of a situation where anyone would *intentionally* fly an airplane into the building, let alone with the sole purpose of destroying the building. They *were* designed to withstand the impact of a Boeing 707, the largest passenger jet of the time, but they hadn't considered the resultant events that would follow. An impact, in and of itself, is relatively insignificant. Nevertheless, they hadn't planned on someone *intentionally* flying into the building.

Accidents are accidents, but this was no accident. But how would an intentional strike differ in terms of physics from an accident? The hijackers purposely picked the largest planes they could get their hands on, and ensured they were *fully* loaded with fuel for a trans-continental flight. In an accident, the plane, *more than likely* is *not* aimed at the center of the building.

The likelihood of the mass of the aircraft reaching the core is less significant in an accident. Also, by the alignment of the air traffic control routes among the three major airports in the area, it's highly unlikely a plane would intentionally cross Manhattan Island. Controllers would notify the pilot to alter course to avoid the buildings. So, in an accident, it is far more likely for the plane to clip the building, rather than plow into it. In such a case, the structure of the buildings was more than sufficient to withstand the impact and resulting fire.

What doomed the buildings was the huge amounts of burning jet fuel streaming down the elevator shafts. In an accident, a collision with the building would be most likely to occur when the plane was landing, not taking off or during transitional flight, so the quantity of fuel on board would be significantly less than what these planes had available. The interesting thing is that in a building of similar height built today, that core would almost certainly be super-high-strength concrete. Enough of the plane's inertia would've been lost during transition though the shell that anything that reached the core wouldn't have penetrated the core. So a lot less of the plane would've made it to the core than with the twin towers.

If you were to compare the destruction of the building using, say, a cruise missile, although much smaller
in size, the missile is designed to penetrate the shell, and then detonate in the core. The terrorists didn't have such technology available, so they had to choose something of sufficient mass to penetrate the shell *and* core, and since they had no explosives available, they had to choose something with a sufficient quantity of flammable materials to generate the intended result. A Boeing 767, fully loaded for a trans-continental flight (obviously)met those requirements. The plane itself never acutally detonated, it disintegrated, in the process, releasing highly flammable liquids, which were ignited by heat generated by the engines, the friction of the impact with the building, and the severed electrical systems within the building. And much of the fuel was atomized on impact, creating a highly explosive mist within the building envelope. What didn't atomize ran down through the core, spreading the "accellerant" through enough floors to affect the structural integrity.

Now then, now that we have the physics of things that burn, let's talk about some other factors that I believe contributed to the fall of Towers 1 and 2. Let's talk about building codes, shall we? In general, building codes are a pretty recent development in the construction industry. (So is the Americans With Disabilities Act, but that's another post.)

Building codes came about in earnest in the U.S. after the massive fire in the MGM Grand Casino and Hotel in Las Vegas, NV in 1980. Of all of the fatalities, the vast majority of them were in the hotel tower due to smoke inhalation, not from actually being burned to death (though it was a spectacular fireball indeed--it cleared a distance of two football fields in less than eight seconds and burned gamblers to a perfect crisp with their hands still clutching the levers on their slot machines). The mechanical and elevator shafts in the hotel tower channeled the smoke right up to each floor, thereby asphyxiating the hotel's guests on floors that the fireball never touched. Since then, the primary goal of building codes is to first save lives and allow people to safely exit the building; second, to save the structure so that the non-loadbearing elements can be rebuilt; and third, to save contents and possessions if possible. Sprinkler systems help do this, but it's a secondary line of defense. Structural integrity and egress (exit) paths are the first line of defense.

The World Trade Center was built in 1971-1972, eight years before building codes were in wide implementation and enforcement. Hence, I don't know that any spray-on fireproofing (an image of which is forthcoming in tomorrow's Detail of the Week) was applied to the structure. Without fireproofing, the immense heat of the fire could very easily have deformed the columns and allowed the building to collapse. Also, much of the Twin Towers' structure was along the exterior skin in order to free up the inside of the building for office space. When the exterior skin was ruptured by the plane, the building lost a great deal of its structural integrity. The main innards of the Towers, called the "core", which consists of the elevators, the stairs, toilets, and the mechanical and electrical shafts and rooms, take up the very center. See the photo below. (I know it's not easy to see, but I've marked where the stairs are in the plan.)

The WTC's tenants used these stairs as regular circulation instead of taking the elevators one or two floors. Given that due to the size of each floor, as many as 300 people could work on each floor at the same time, that's a lot of people to try to funnel down the stairs. Imagine trying to funnel 300 people per floor times dozens of floors down the stairs...while fully loaded firefighters were coming up the stairs. Then imagine some of the people coming down the stairs having to carry some of their fellow coworkers because the person gives out 30 floors down and still has another 20 or 30 to go to get to the street. Two normal people need at least 5'-0" of width to pass each other going in opposite directions, but let's add that one person is carrying a person while the person going in the opposite direction is wearing a full jacket, a 60-lb pack, an axe, and a breathing apparatus.

Need a little more width than 5'-0", don't you?

Also, elevators often shut down when there's a fire. They go to the bottom of their shafts and pop their doors open to show the firefighters that no one is trapped inside. However, in tall hospitals (like Pomme de Terre), at least one elevator will be operable in a fire so that staff can evacuate incapacitated patients if they're on the floor where the fire is located. It sounds like the Twin Towers could have used a few emergency-operating elevators. These same elevators can be used by firefighters to get up to the floor where the fire is burning. Perhaps the fighters couldn't use them though, because the planes had severed the power supply and shorted them out. I'm guessing about this part, don't know for sure.

Furthermore, human nature played a part in the disaster. Some tenants reported being told to go back in the building after the planes had been burning for a while because "everything was okay and the fire was under control". Many of us--surely all of us--were so shocked to see what was happening that a part of us just couldn't fathom it, couldn't accept it, and wanted everything to be okay. Let's face it, none of us were prepared for the immensity of 9/11, and we really had no plan to deal with it. So the tragedy of 9/11 was due to the condition of a purposeful air strike, an absence of code and fire safety compliance at the time of construction, and a lack of a plan to handle the humans leaving the building.

The design of the Twin Towers, plus the luck of the planes colliding so high up on the buildings (in the top quarter of the tower), allowed the floor slabs to pancake on top of each other and fall fairly cleanly onto each other. Imagine how much worse it could have been if they'd toppled over from the middle and dropped floors 55 through 110 onto neighboring buildings. Still frightening though, is that what fireproofing that was in the building was acheived through the use of asbestos, a carcinogen so potent that I was told as an intern if I so much as peeked into an asbestos-clad ceiling they'd have to evacuate the building. I've heard some reports that they did asbestos abatement on the towers in the 90s, but I have to wonder if some tiny friable fibers of 220 stories of asbestos are still floating around Lower Manhattan.

Okay, I acknowledge that this was a lot of info, and I'm sure other WAD readers out there will have something to add, contribute, or dispute. But Wandering Author asked me for an opinion, and given my extent of knowledge, that's what I have to say.