The Sampoong Department Store Collapse

If you wanted to indicate security and sturdiness, you might say that something is “safe as houses” – because, after all, what’s safer than four strong walls and a solid roof? We take for granted the idea that the buildings which surround us are built to endure, whether that’s the homes in which we live, the buildings where we work or the places we go to spend our leisure time. Unfortunately, that’s not always true.

If you like shopping, there’s nothing better than a big department store, where everything you want is under one roof. And if it’s a high-end department store, in one of the most fashionable parts of the city, all the better! The Sampoong Department Store in Seoul, South Korea, was exactly that. It was located in the Seocho area of Gangnam – yes, as in “Gangnam Style”. The infamous 2012 hit was a satire on the luxurious lifestyle connected to the area, and the common stereotype of people who’ll live on cheap ramen so that they can afford to spend conspicuously, drinking in expensive coffee shops and shopping in luxurious boutiques.

This association with wealth and status began with a development boom from the 1960s onwards. As South Korea recovered from the Korean War, it grew at an extraordinary speed, recording the fastest rise in average GDP per capita in the world between 1980 and 1990. In Seoul itself, there was a specific building boom in the run-up to the 1988 Olympics which were hosted in the city – and the construction of the Sampoong Department Store was part of that boom.

Construction began in 1987, and was completed in 1989. After it opened in July 1990, the huge, bright pink structure attracted some 40,000 visitors every day. It had four basement levels and four floors of shops above ground. The fifth floor of the building housed a number of traditional Korean restaurants.

For most people in the building, Thursday June the 29th, 1995, was a day much like any other, except for the fact that the air conditioning had been turned off. This was unusual for Seoul, with its hot, humid summers. Yoo Ji-Hwan, one of the store’s teenage employees, remembered customers getting angry, and asking, “Why does a prestigious store like Sampoong not have working air conditioning?”

Of course, as is usually the way with these things, it was a decision that had been taken by management, and the store clerks on the ground didn’t really know why.

Park Seung-Hyun, a nineteen year old employee working in the children’s department  on basement level one, later recalled,

“Even with the air conditioner off, we all kept working. It was just like any other day. Customers continued shopping and workers kept working.”

They did hear that the restaurants on the fifth floor had been closed; a crack had been found. Later in the afternoon, that the fourth floor had been closed for trading, too. However, as the city’s offices closed for the day, the usual rush came through of customers shopping on their way home, and the rest of the store remained open.

At about twenty to six, there was a loud bang from the top floor. A few minutes later, there was another bang, this time louder. Then, the building’s alarms started sounding, and people started to panic.

Park described that moment.

“From across the store there was a sound like a subway train entering a station, and when we heard that sound people started running here and there. Suddenly a piece of concrete dropped on my head and I was knocked unconscious.After I awakened I was completely surrounded by darkness and all sides around me were closed in. There wasn’t any room. I cried for help and banged on the steel pipe beside me, but they couldn’t hear me from outside.”

At that moment, she didn’t know that the entire south wing of the Sampoong Department Store had collapsed; all five floors, right down into the basement. It had taken about twenty or thirty seconds, and there had been approximately 1,500 people inside.

Source: Wikimedia Commons

A friend of Park’s, Seo Hye-Jin, was supposed to meet her after work. Instead, she saw the ruins of the building.

“I am shocked. So many injured and bleeding. The dead being carried away. I start scrambling at the rubble with my hands. I keep digging. I don’t know why I’m doing it, I just need to do something.”

Professional rescue teams were quickly on the scene. Ahn Kyung-Wook, a firefighter, was amongst them.

“In one word, it was hell. It made me wonder how this kind of disaster could have happened in a normal society, not under condition of war. I felt futile and so shocked at the gigantic proportion of the disaster.”

Throughout the wreckage of the building, those lucky enough to be near the surface were crawling or being dragged out. However, many were trapped deep beneath tons of concrete.Park was, in some ways, fortunate; she had not suffered any significant injuries when the building collapsed. However, she was trapped, and things looked bad.

“In the space where I was stuck, I could stretch my arms… the space on my side was slightly wider. But soon afterwards the ceiling started coming down and I could not turn my body around.”

Yoo Ji-Hwan, who had also been working in basement level one, had not escaped so unscathed.

“I can feel a hole in my head so large my finger can go through it, that’s how big it is. And I can feel something squiggly in a cut in my back, like my intestine. I don’t want to die. As I look around I think it’s just a wall that’s collapsed on me. I try calling out but there’s no answer. I think it’s just me who’s stuck here.”

The rescue work was started quickly, but it was difficult. Firefighter Ahn later told a Discovery Channel documentary,

“Generally speaking, the rescue equipment proved to be ineffective in a large scale disaster. The rescue equipment consisted of; heat detector, sonic detector, equipment that could even detect human breath, search dogs etcetera. However, because everything was crumbled and buried underground with over 500 casualties, even the dogs were ineffective. Because the area was large and so chaotic, electronic heat detector was no use. Even though we used large cranes, we were worried about the possibility that there could be some survivors underneath, that they might be crushed. So we lifted all the pieces one by one.”

Fire and smoke also caused issues for the rescuers; the store had an underground car park, and it was believed that cars crushed down there were fueling those fires. Firefighters spread water across the site to control the flames.

Source: Wikimedia Commons

Inside the rubble, many of the survivors struggled to hold on to hope. One, a high-school teacher named Hong Sung-tae, dictated his will to a stranger nearby. Both were freed late on Friday, after more than a day beneath the rubble. From his hospital bed, Hong told reporters, “I don’t know whether I am alive or dreaming.”

Yoo Ji-Hwan later said that she had come very close to despair.

“I think a lot about the short life I have had. All of those close to me. My friends. And especially my mother. I think about killing myself. I can’t take the horror any more. But then I realise that actually it’s very easy to become very selfish and not think of the effect it can have on the people I love.”

Outside, fears for the safety of the rescuers were growing. One towering wall remained at the far end of the collapsed building, and it was now unsupported. The mayor of Seoul called off the search for survivors. In response, the families of the victims and the missing protested in the street. Eventually, the wall was stabilised using guy ropes and cables so that the search could resume.

Source: Wikimedia Commons

52 hours after the collapse, there was jubilation from the rescue workers and the families who had gathered around, as 24 people were pulled alive from the wreckage. They were all cleaners, who had been fortunate enough to be inside a basement dressing room which remained intact. However, they had little air and no food or water. Some of them drank their own urine to survive.

Once the rescue workers found them, they used a long steel pipe to provide the survivors with air, food and water as they cleared a path for their escape. That took over thirteen hours, as they had to cut through concrete slabs and metal reinforcing rods. Even then, the survivors had to be greased up with vegetable oil and liquid soap so that they could be pulled out.

Han Kyung-Sok, one of those survivors, later told reporters, “We held hands and encouraged each other not to lose hope. I desperately wanted to live, even though I felt so miserable and dreadful.”

Even with moments like this, it was difficult for the rescuers to maintain hope. A firefighter named Kim Jung-Hoon told reporters that his team had pulled a survivor out on the first day, but since then had only found dead bodies.  

“Every time I see one person dead, I tell myself that we must hold hope because there may be one more person still alive. The only thing on my mind is that I have to rescue someone still alive. I don’t have any space in my mind to think of anything else. I’m exhausted, but there is no place to cry on anyone’s shoulder. The site is so devastating, so horrible, nothing else can fill my mind.”

By gathering information from survivors and witnesses, the rescue teams knew roughly where to look for surviving employees – they would have been at or close to their work stations at the time, which narrowed down the field a little. However, they still had to work out where that location might have ended up after the collapse.

After a week, the hope of retrieving any more survivors seemed distant. The rescue operation became more of a recovery operation. Heavy machinery, which the rescuers had initially been loathe to use in case it injured buried survivors, was now employed; in the summer heat, buried bodies were decomposing.

However, it was not all over. Ten days after the collapse, a salesman named Choi Myong-Sok was rescued. He said that he had survived by drinking rainwater, and kept his spirits up by playing with a children’s toy. There had been other survivors nearby at first, but they had died. He thought that they might have drowned on the water from the firefighter’s hoses and the monsoon rains – the same water which had kept him alive.

Meanwhile, Yoo Ji-Hwan was still injured and trapped inside a hole four and a half feet long and nineteen inches wide.

“Around by my foot suddenly it just opens up. There is a hole. And I can hear a voice asking, is there someone in there?I can’t really explain it but it’s just happiness I feel like I’m flying. That I’m freed from everything. Everyone knows who I am and even if I die now everything I’ve worried about has been taken away.”

She had been trapped for twelve days.

Source: Wikimedia Commons

Sixteen days after the building’s collapse, it was even harder to believe that anyone might still be alive, but firefighter Ahn Kyung-Wook held on.

“If you convince yourself there are no more survivors, you cannot work as a rescuer, so right up to the last moment I never lost hope that some people might be alive. When I lifted a piece of concrete, I heard something.”

It was Park Seung-Hyun.

“I hear loud machinery above my head and I think this is it, im going to die. I start banging with all my might.The machines stop and I hear a voice call out, is anybody down there? I am thinking now I am saved. I am going to live.”

Ahn moved rubble away, opening up a hole just large enough to crawl in.

“It was pitch dark but when I turned my head torch in the direction of the voice Park’s face was right there. We were face to face.”

Other rescuers joined in, digging with their bare hands to pull Park out.

“I told them, I have no clothes on. They said not to worry and they pulled me out and wrapped me in a blanket. After the rescue workers touched my hand I felt, I’m alive, I’m going to be okay.”

Park’s survival was practically miraculous. While it’s possible to survive three weeks without food, you can’t expect to last more than three or four days without water. Her tiny space beneath the rubble was hot and humid; enough water from the rains and the firefighters’ efforts must have filtered through to keep her alive.

She was the last person pulled alive from the wreckage of the Sampoong Department Store; after that, only remains were found. Many relatives of those still missing found it impossible to give up, though. Six months after the collapse, some still camped out near the site. Kang Eun-Hee, who lost her 19 year old daughter, told reporters, “When I go home, I feel uneasy and I don’t know what to do. But when I come to this place, I can calm down.”

In total, 502 people had been killed, and a further 937 injured. It was the largest peacetime disaster in South Korean history, and everyone wanted to know how it had happened.Professor Lan Chung, an architectural engineer from Dankook University, was well qualified to answer that question.

“After having taught structural engineering to several thousand students, I can not help but feel a moral and social responsibility as an expert. So I rushed to the site of the collapse to join the investigation team, trying to explain how this disaster could have happened.”

As with any disaster investigation, it was important to consider all possible causes, and rule them out one by one until the true cause was all that remained. Initially, a gas explosion seemed likely – a store employee had reported smelling gas in the days before the collapse. However, the fires that followed the collapse were not consistent with a gas explosion.

Another theory that had to be ruled out was that a bomb may have caused the collapse. Seoul stands only 56kilometres – 35 miles – from the border with North Korea, and relations between the two countries had remained strained since the end of the Korean War in 1953. North Korean agents had been responsible for the bombing of a Korean Air flight in 1987, killing 115 people. If they were to strike again, the luxurious store would have been an apt symbol of the South’s capitalism to strike against.

However, the nature of the collapse made it clear that there had not been an explosion. In the case of a bombing, like the Oklahoma City bombing just a couple of months earlier, parts of the building would be blown outwards in a recognisable radius; it was apparent that in this case, the building had come straight down.

Source: Wikimedia Commons

With those possibilities ruled out, the field was narrowed down. Another investigator, Professor Hyungsik Chung of Hanung University, said,

“There are two major reasons for collapse. One is how the structure was constructed and the other part is the foundation… If the foundation is weak, the building may settle or start sinking, and if the building settles, the structure will be damaged.”

The Sampoong Department Store had been built on land which had previously been a landfill. If that land had not been reclaimed appropriately, the foundations could easily be compromised.

However, when investigators took a series of core samples from the ground to check the stability of the foundations they found that this was not the case.

“The core sample shows that its foundation was firmly attached to a layer of bedrock. Furthermore, examination of the basement level of the building revealed that the foundation had survived the collapse relatively intact. The foundation was quite stable.”

This left only the construction of the building, but this still encompassed a range of factors to consider.

Source: Wikimedia Commons

The store was made from concrete, using a system called flat-slab construction, so the concrete itself had to be investigated. Professor Lan Chung explained;

“Concrete is composed of three parts; cement, water and aggregate. The combination has to be precise. If there is too much or too little of any one component, then the strength of the concrete will be compromised.”

Samples of the concrete from the store were subjected to a pressure test to check their strength. This basically consists of applying increasing pressure to the sample to see how much it can take before it fails – and in what way it fails, whether it crumbles away or fractures. The results of the test showed no problems – the concrete was strong enough.

With the materials ruled out, now the investigators turned to the design. According to Professor Lan Chung, “Flat slab system is as strong as any other, but it requires more precise planning than other structures and there is no margin for error.”This is where the inconsistencies of the Sampoong Department Store began to be revealed.

The building had not originally been planned as a five-floor department store, but as a four-floor apartment building. The Sampoong Group had decided to make changes after construction had begun. Their original builders, Woosung Construction, had objected to the changes, and had been dismissed. An in-house building company had completed the work.

Because of regulations that restricted the number of trading floors a department store could have, the fifth floor was initially intended to be a rollerskate rink. However, again, changes were made by the Sampoong Group, and instead the fifth floor was given over to restaurants. This may not seem particularly important, but it was actually very significant.

In a traditional Korean restaurant, customers sit on the floor – and to ensure their comfort, they use underfloor heating. This requires pipes to be run throughout the floor, and as a result the concrete of that floor needs to be thicker. Restaurants also come with a lot of heavy kitchen equipment. The net result was that the fifth floor was now three times heavier than originally planned.

Flat slab construction means that each floor is a concrete slab, supported by a number of columns which distribute the weight evenly. Any changes to that weight must, therefore, be reflected in changes to the columns; a heavier building needs stronger columns.

The columns were originally supposed to be 80cm in diameter, with 16 reinforcing rods running through them. When Professor Chung looked at the drawings, he discovered that, far from having been made stronger, they had been reduced to 60cm in diameter, and had only eight rods.

When Professor Chung calculated the effect that this reduction would have, he found that it reduced the building’s strength by nearly half. However, buildings are usually designed with a large safety margin, so it should still have been strong enough.

Source: Wikimedia Commons

Except that there were further problems with the columns, noted by structural engineer Lee Moon-Gon.

“The connection area between the column and the slab is very critical because the columns directly distribute the load… We eventually found that some columns were missing the drop panels between the slab and the column, and the drop panel is essential in a flat slab structure.”

The spacing between the columns also caused some concern; if they had been closer together, they would each have borne less load, but instead they had been spaced widely to create as much retail space as possible.

Then, another factor was discovered; one which was supposed to have made the building safer. Fire shields had been installed around the escalators; in the event of a fire, these shields would drop to ensure that the flames and smoke could not spread to adjacent floors. Unfortunately, installing these shields had meant cutting into the columns around the escalators, reducing the support they provided by as much as 25 percent.

While all these factors combined to put the building on the verge of collapse, there was one more mystery for the investigators to solve – why had it happened then?

As Professor Chung put it,

“There always exists a critical point. If you go beyond that point, the building collapses. It can take a long time for a building to reach the critical point before it collapses. But then sometimes you just need a drop of water, one drop of water, and the destruction starts.”

They still needed to identify that one drop of water, the final factor which had actually triggered the collapse.

Several members of the store’s management had been arrested and questioning one of them led to the answer.

The facilities manager, Mr Lee, told the investigation team that there had been significant issues earlier on the day of the collapse. That morning, he had been called to one of the fifth floor restaurants because there were cracks around one of the columns. These were not small cracks, either – they were described as being the size of a man’s fist. In other parts of the fifth floor, the floor was visibly buckled, and just before midday some of the kitchen staff reported hearing cracking sounds from the ceiling.

The building’s management brought a structural engineer in that afternoon. He had taken pictures of the cracks and bulges. According to some sources, he told senior staff that the building was sound; others say that he advised them to evacuate the building, but was ignored. Those senior staff members did, of course, leave the building themselves.

This information allowed the investigators to pinpoint the column which had precipitated the collapse, and from there they were able to discover how and why.

Two years earlier, following noise complaints from neighbours, three large air conditioning units on the roof had been moved. Although they were very heavy, they were not lifted using cranes. Instead, they were placed on rollers and dragged across the roof. Noticeable cracks were left behind, but nothing was done about them.

The investigators concluded that the air conditioning had been dragged directly over column 5E – the one which had been cracked on the morning of the collapse – and this had fatally weakened it. Over the next two years, every time the air conditioning was turned on, vibrations were sent through the roof and the columns, gradually widening the cracks.

Management were aware that the air conditioning was causing vibrations; this was why it had been switched off that day, but it was too late. Column 5E was no longer able to bear the load. Finally, it gave way. Its share of the load was transferred to the other columns, which in turn gave way, and the entire structure failed. The roof fell down onto the fifth floor, and successively every other floor collapsed, too.

Once the first column failed, it took only about twenty seconds for the entire building to pancake downwards. However, the collapse of the Sampoong Department Store had effectively begun more than five years earlier – it began before the store ever opened.

As a result of the investigation’s findings, criminal charges were brought against several members of the Sampoong Group’s senior management.Chairman Lee Joon was charged with criminal negligence and was given a prison sentence of ten and a half years. On appeal this was reduced to seven and a half years. He died in 2003, shortly after his release.

His son, the store’s president Lee Han-Sang, was also convicted and sentenced to seven years for accidental homicide and corruption.

However, responsibility for the collapse went beyond the store itself, which had passed regular inspections right up until the collapse.

Hwang Chul-Min, former chief of the Seocho ward where the store was located, was sentenced to ten years after being found guilty of accepting a bribe of twelve million won. Other officials received sentences of between eight and eighteen months. In total, 25 people received either prison sentences or were fined.

This level of corruption raised concerns about other buildings in Seoul. If one company could get away with shoddy construction through bribery, what had stopped others doing the same?

The shocking answer was, nothing at all. A thorough inspection of Seoul’s skyscrapers revealed that only one in fifty could be called safe. Four out of five needed major repairs, and one in seven had to be rebuilt.

Source: Wikimedia Commons

Jeong Gwan-Jin, a lawyer who lost three daughters in the collapse, said, “People should do their best at their jobs. This accident happened because they didn’t.”

Survivor Park Seung-Hyun echoed that sentiment.

“If they were to build a building for themselves to live in, they wouldn’t have built it so carelessly and poorly. If people were to construct buildings with the spirit and attitude that they were building their own homes, I don’t think there would be another disaster like the Sampoong collapse.”

There is nothing to identify the site of this tragedy today. Although the families of the victims asked for a memorial on the site, it was instead sold to a private developer. Luxury apartments now stand there, everyday life carrying on on the spot where more than five hundred people died. A memorial was instead erected in the Yangjae Citizens’ Forest, a park approximately half an hour’s drive away.

Source: Wikimedia Commons

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