The Grenfell Tower Tragedy

In 1974, a new high-rise public housing apartment building opened in West London.  Called Grenfell Tower, it was 24 stories tall and designed to house as many as 600 people in 120 apartments.  Photographs of it taken before a renovation in 2015 show large windows on one side and smaller ones on the adjacent side. 

In 2014, as reported in this blog, the 63-story Address Hotel in Dubai, United Arab Emirates went up in flames as aluminum-clad foam-plastic panels called architectural cladding or sandwich cladding on its exterior caught fire and quickly spread the conflagration to most of the outside of the building.  Amazingly, no one died in that fire, due to a quick evacuation order by the authorities and the failure of the fire to spread to the interior of the hotel rooms.  But this was only one of numerous exterior-cladding fires that have resulted from the use of flammable architectural materials on buildings that are too tall to be reached conveniently by fire ladders.

In 2015, the Kensington and Chelsea Tenant Management Organization, the bureaucracy in charge of public housing in the Grenfell Tower district, decided to do a renovation, possibly to improve the structure's insulation and lower heating costs.  New windows were installed, thermal insulation was added, and to cover these changes, sandwich cladding panels were installed to cover the four exterior side walls. 

Some, perhaps most, of the cladding was made by the U. S. firm Arconic, which sells various types with different kinds of plastic between the outer aluminum sheets.  A cheaper type uses polyethylene plastic, but is not recommended for structures over 10 meters (33 feet) tall.  A slightly more expensive type is fire-resistant, as was the thermal insulation used underneath the cladding.  But even fire-resistant plastic can burn under some conditions.

When constructed, the building had no sprinkler system, but the apartments were piped for gas cooking and gas lines were present throughout the building.  Each apartment had fire detectors, but a residents' organization called the Grenfell Action Group has voiced complaints to authorities over the past few years about outmoded and non-functional fire extinguishers, flammable clutter in hallways, and other fire-safety issues, with little apparent response.

Residents of the Grenfell Towers, as were most other residents of London, had been instructed in case of fire to remain in place to be rescued by firefighters, rather than attempt an escape on their own.

In retrospect, the Grenfell Towers fire was a disaster waiting to happen:  an aging, open-style building without a sprinkler system but full of gas lines, covered with apparently flammable sandwich cladding outside potentially flammable insulation material, crowded with up to 600 residents who had been told to stay in their apartments in case of a fire.  And in the early morning hours of June 14, 2017, a fire broke out, reportedly in a kitchen on the fourth floor.

No sprinkler system or fire extinguisher succeeded in stopping the blaze before it ignited the exterior cladding, which in a matter of a few minutes spread the flames upward and eventually completely around the structure.  Many survivors got out by disobeying the orders to stay in place.  As of this writing (June 18), the estimated death toll is 58, and is expected to go higher.  If this is confirmed, it will be the largest number of people to die in a single fire in London since the Blitz of World War II.

Fires that kill lots of people at once are not that uncommon, but usually they happen in crowded single-room venues such as nightclubs where fireworks or other sources of ignition catch flammable materials on fire.  The spectacle of an entire high-rise building going up in flames because of flammable exterior cladding is something that is not supposed to happen in modern "fireproof" structures.  But the invention of a cladding material that is light, inexpensive compared to concrete, solid steel, or aluminum, and reasonably durable has led to its use and abuse throughout the world.  And as numerous cladding fires have shown, you can take the most fireproof building in the world and surround it with thin, flammable sheets exposed to a lot of air, and what you get is a giant Roman candle waiting to be set off. 

The Grenfell Towers fire may become a turning point in the politics and regulations of exterior cladding, similar to the infamous Triangle Shirtwaist Factory fire in New York City that killed 146 garment workers in 1911.  Like many of the residents of the public-housing Grenfell Towers, most of those who died in the 1911 fire were poor immigrants, though they died on the job amid flammable clothing materials, not at home surrounded by flammable architectural panels.  The Triangle fire had the good result of inspiring calls for improved fire-safety building codes and regulations, which if implemented can prevent tragedies like this.

British Prime Minister Theresa May, already in a politically weak position, has been jeered and attacked for what many saw as her inadequate response to the tragedy.  She and other politicians could turn this situation to the benefit of their country by leading a thorough investigation into the causes of both the Grenfell Towers fire and other similar fires in which flammable exterior cladding has played a role.  Then, they could take vigorous and definite action with regard to both existing and future architectural cladding that has any significant chance of short-circuiting fire safety by enabling the spread of a fire on an otherwise fireproof structure's exterior. 

It is ironic that after making people suffer for centuries the hazards of living in wooden structures that were chronically prone to burn down, nineteenth-century architects thought they had solved the problem of fire with concrete-and-steel structures, only to torch their triumphs in the last few decades by using what amounts to cheap window-dressing materials that burn like fireworks.  If I were an architect, I would be afraid to show my face in London after the Grenfell Towers tragedy. 

The most basic ethical requirement of a profession is that the professionals look out for the interests of those average citizens affected by their professional activities, citizens who have no way of knowing what hazards they could be subject to and how to avoid them.  I would be surprised if more than a few residents of Grenfell Towers knew anything about sandwich cladding, or the fact that under the right circumstances it would burn.  Well, everyone knows now.  And I can only hope that this knowledge gets applied to similar dangerous situations, and we do whatever it takes to keep another Grenfell Towers fire from happening anywhere, ever again.

Sources:  I referred to news reports about the Grenfell Towers fire carried by the Australian Broadcasting Company on June 17 at http://www.abc.net.au/news/2017-06-17/grenfell-tower-panels-not-suitable-for-tall-buildings/8627790, the Canadian Global News at http://globalnews.ca/news/3536188/grenfell-tower-fire-death-toll/, and the Wikipedia articles "Grenfell Tower fire" and "Triangle Shirtwaist Factory fire."  My blog on the Address Hotel fire in Dubai appeared on Jan. 4, 2016.

West One Year Later: Will It Happen Again?

On April 22, the U. S. Chemical Safety Board held a news conference to present its recommendations about how to prevent another disaster such as the one in West, Texas that killed fifteen, injured over 200, and caused millions of dollars of property damage on April 17, 2013.  So far, not a lot has changed in terms of federal or state regulations pertaining to ammonium nitrate, the fertilizer chemical that exploded on that fateful day.  But a fertilizer trade organization has issued a set of recommendations that, if followed, will go some distance toward reducing the chances that another disastrous accident involving the chemical will happen again.

As long ago as 2002, the Chemical Safety Board recommended that ammonium nitrate be included in OSHA (Occupational Safety and Health Administration) and EPA (Environmental Protection Administration) regulatory programs, but these agencies have not yet chosen to act on these recommendations.  Ammonium nitrate falls in a gray area between chemicals such as nitroglycerin or TNT that are clearly dangerous, and others such as sand that are harmless.  Under most circumstances, ammonium nitrate can be handled with little or no risk.  But under certain combinations of heat, pressure, and/or shock, the chemical detonates, transforming many tons of solid matter into hot gases that expand explosively, as they did in West. 

In response to the West accident a trade organization called The Fertilizer Institute issued a fourteen-page booklet to its members last February with the title "Safety and Security Guidelines for the Storage and Transportation of Fertilizer Grade Ammonium Nitrate at Fertilizer Retail Facilities."  The title does not promise exciting reading, though the legalese and lengthy definitions of different types of ammonium-nitrate fertilizer are enlivened by color photos of fertilizer manufacturing and handling installations.  The pamphlet summarizes most of the precautions which, if followed, would have gone a long way toward preventing the West disaster. 

These measures fall into two categories: (1) ways to prevent ammonium nitrate from exploding in the first place, and (2) ways to avert death and destruction if a fire breaks out where ammonium nitrate is stored, and the stuff explodes anyway.  The prevention measures are more or less what you'd expect:  things like storing the material in non-combustible bins, rather than wooden ones as were used in the West firm; installing sprinkler systems or other fire-prevention and fire-fighting facilities; and treating places where ammonium nitrate is stored like flammable-material storage areas (no-smoking signs, no sparks or flames nearby, etc.).  Because an exact cause of the fire at West that led to the explosion may never be found, we cannot know for certain if these precautions would have prevented the tragedy.  But obviously, they are good things to do, and if fertilizer retailers around the country follow these prevention guidelines, the chances of another such accident will be reduced.

The second category of recommendations is more problematic.  It involves informing the wider community, including first-responder agencies, that ammonium nitrate is stored in the facility and should be treated with extra caution.  By the nature of the business, many fertilizer retailers are located in semi-rural or thinly populated areas.  These locales are often served by volunteer fire departments, and while volunteer firemen theoretically should be trained as well as full-time paid firefighters, the reality is that their training may be on the sketchy side.   The Chemical Safety Board concluded that the first responders in West did not know of the dangers presented by the large quantity of ammonium nitrate stored at the plant where they responded to what appeared at first to be an ordinary fire, and were much too close for safety.  Consequently, when the plant exploded, most of the people who died were firefighters.  The guidance handbook says "The rule of thumb is if outside emergency responders are necessary, do not fight AN [ammonium nitrate] fires.  For fires that have engaged AN, plans should focus on evacuation of the area."  In other words: don't fight, run. 

While the trade-association brochure's advice is good, it has no legal standing, and firms are free to adopt its recommendations or ignore them.  Simply as a matter of asset protection, I would hope that fertilizer retailers who sell ammonium nitrate are at least considering an upgrade of unsafe storage facilities, and the brochure provides good guidelines as to how to carry this out.  However, the informational side of the recommendations may be harder to implement.  A business owner may feel some reluctance in volunteering the information to local authorities that his facility harbors material that might reduce a wide swath of his neighborhood to rubble.  Nevertheless, there may be courageous and conscientious owners who will do such things. 

Both the Chemical Safety Board and various other authorities have called for tighter compulsory regulation of ammonium nitrate storage and transportation.  This is a political as well as a technical and ethical matter, and politics these days tends to go to polarized extremes.  On the one hand are those who favor centralized uniform federal regulations for all sorts of things, including ammonium nitrate.  On the other hand, a prominent plank in the Tea Party platform is the idea that government regulations have gone too far and are stifling free enterprise and economic growth.  The regulations contemplated with regard to ammonium nitrate vary from rules about how the stuff is stored to rules about notification and training of local first responders.  It seems to me that sensible regulations requiring the exchange of information, perhaps implemented by some sort of web-based registry, would be the least costly way to make sure that at a minimum, any firefighters responding to an ammonium-nitrate fire would know what they are dealing with and would take appropriate precautions. 

One way of dealing with this information problem is by the use of fire codes.  However, the state of Texas has a strong history of anti-regulatory bias.  In fact, counties with low population density in Texas are actually prohibited by state law from enacting fire codes at all.  So around July and December, you see roadside fireworks stands popping up for a few weeks with nary a concern for any safety beyond the immediate self-preservation of the owners in case a customer drops a burning cigarette. 

So far, the only concrete public action toward preventing more ammonium-nitrate fertilizer disasters has been the Fertilizer Institute's brochure.  While they deserve credit for their efforts, only time will tell whether enough has changed to keep another fertilizer plant from blowing up, or to save lives if it does.

Sources:  The news conference in Dallas on Apr. 22, 2014 held by the Chemical Safety Board was summarized by a UPI report at http://www.upi.com/Top_News/US/2014/04/22/US-investigators-Better-regulation-could-have-prevented-deadly-fertilizer-explosion/4731398190424/.  The Chemical Safety Board's own statements at the conference can be downloaded at http://www.csb.gov/assets/1/16/Statement_-_News_Conference_(Final).pdf.  The Fertilizer Institute recommendations can be found at http://www.tfi.org/ammonium_nitrate_guidelines.  And I blogged on the West explosion previously on Apr. 22 and May 20, 2013.

Update on West: Causes and Consequences

Last Thursday, May 16, officials from the Fire Marshal’s Office of Texas and the federal Bureau of Alcohol, Tobacco, Firearms, and Explosives announced that the cause of the April 17 fertilizer-plant explosion in the town of West was “undetermined.”  However, they had eliminated a number of possible causes and narrowed the probable ones to three:  something to do with the 120-V electrical system in the plant, a golf cart stored in the same room with the ammonium nitrate bins, and arson. 

Considering the horrible jumble of wreckage that the explosion left behind, even this much progress in the investigation is laudable.  The investigators did determine that about 28 to 34 tons of ammonium nitrate, a fertilizer ingredient, exploded in the blast that dug a crater ten feet deep and 93 feet wide and caused seismometers to register the equivalent of a 2.1-magnitude earthquake.  It could have been worse:  another 140 tons of the material stored either onsite or in railcars at a nearby siding did not explode. 

The investigation revealed that the ammonium nitrate that exploded was stored in wooden bins next to bins of flammable seeds.  No sprinkler system was in place, and under current fire-code regulations none was required in the industrial facility. 

The reconstructed sequence of events is fairly brief.  At 7:29 PM on the evening of April 17, a fire was reported at the facility.  Unless there were personnel on site that late in the evening, it is likely that no one was present at the time and the first report was turned in only after smoke was visible outside the plant.  So the fire may have had some time to get going before it was reported.  This is significant, because when ammonium nitrate is heated, it can turn from a white powder into a solid mass that transmits shock waves well.

Nine minutes after the fire was reported, firefighters arrived and began to play water on the blaze, which the investigation stated did not contribute to the explosion.  Investigators speculated that as the fire progressed, a piece of heavy equipment might have come loose and fallen onto the now-solidified mass of ammonium nitrate, causing a detonation wave that led to two almost simultaneous explosions, 22 minutes after the fire was reported.  It was these explosions that killed fifteen people, most of them firefighters, and laid waste to 37 blocks of the small town. 

Not involved in the news conference at which these findings were announced, were members of the federal Chemical Safety Board (CSB), an agency charged with investigating chemical accidents with a view toward making recommendations about how to avoid them in the future.  A Dallas Morning News reporter interviewed members of the Board involved in the West investigation, and their work is still continuing.  Rather than focusing on the narrow question of exact causes, the CSB is examining the broader picture of how regulations affected the outcome of the incident and how community responses could have been improved.  Questions have been raised, for example, about the wisdom of storing so much explosive material literally across the street from an apartment complex, and not much farther from a school and a nursing home.  Any time a fire occurs at a facility where large amounts of ammonium nitrate are stored, prudence would dictate that at a minimum, the area within a possible explosion range should be evacuated. 

On July 30, 2009, a fire at a fertilizer plant in Bryan, Texas where large quantities of ammonium nitrate were stored led to the evacuation of thousands of residents of that college town (home to Texas A&M) as a precaution.  Fortunately, the fire burned itself out without incident and no damage outside the plant resulted.  But as the West explosion shows, things could have turned out very differently.  The Bryan incident also differs from West in that the people who accidentally started the fire were the ones who reported it promptly, giving more warning than otherwise.

While regulation is always a two-edged sword that can cause more harm than it alleviates, the West explosion will at least inspire re-examination of the whole complex of federal, state, and local laws, as well as insurance-company practices, that bear on the storage of ammonium-nitrate fertilizer.  Determining the appropriate level of regulation, as well as the appropriate agency or agencies to issue regulations, is not an easy task.  Local officials, especially in smaller towns such as West, rarely have the expertise to come up with customized, science-based regulations about hazardous materials that do not cause problems most of the time.  But federal regulations are a blunt instrument, and customarily matters such as fire codes are left to the states and local communities to decide on.  National organizations such as the National Fire Protection Association (NFPA) issue model guidelines and codes, but it is a state or local option as to whether these codes are made part of local laws. 

The deaths in the West explosion were preventable, and I for one hope that the memory of this tragedy will lodge in the minds of firefighters, code-enforcement officials, and governmental agencies who are in a position to keep such things from happening, or at least lower the chances of them happening, in the future.  The sharing of basic information and knowledge about how much of what stuff is stored where needs to be mandated so that first responders know both what they are dealing with and what is prudent to do in a given situation.  Firefighting is a hazardous job, and loss of life in the line of duty is one of the risks that firefighters take on when they join their companies.  But if better information and procedures, even if mandated by the federal government, will keep both firefighters and their communities safer in situations such as what happened in West last month, it may be time to change the way things are done.

Sources:  I referred to an article on the West investigation news conference published on the Dallas Morning News website on May 18 at http://www.dallasnews.com/news/west-explosion/headlines/20130518-in-west-investigators-focus-shifts-from-explosions-cause-to-closing-safety-gaps.ece.  I also used an article from the KRHD-TV website for information on the Bryan, Texas evacuation, found at http://www.abc40.com/story/10823244/ammonium-nitrate-fire-forces-mass-evacuation.