Death and Calamity: The Sampoong Department Store Collapse Explained
History is full of tragedies, but the ones that tend to resonate with us the most are the tragedies that never needed to happen in the first place. Whether the cause is ignorance, greed, naivety or plain ole stupidity, there's no shortage of instances in recorded history where a lot of people died for basically no reason. When you read about the Sampoong Department Store collapse of 1995, it will likely strike you that its cause doesn't fit into one little neat box. In fact, it can be attributed to ignorance, greed, naivety and stupidity,
A Historical Primer:
Having emerged from the Korean War in the 1950s with almost the entire country utterly devastated, South Korea had rebuilt with dizzying speed — and apparent success. In the early 80's, the capital, Seoul, was chosen as the location for the 1988 summer Olympics.
While South Korean firms were noted for their high quality work overseas; at home, construction standards and oversight were often lacking. Partly a product of the period of rapid post-war growth, when many companies adopted a "build now, repair later" approach in order to get the country moving as fast as possible.
Initially, the Sampoong department store was set to become a four-story residential apartment complex, to be built by a company called Woosung Construction. Sampoong hired Woosung Construction to lay the foundation in 1987 and also to serve as project supervisor — an arrangement that can lead to abuse.
However, partway through the process, Lee Joon, the head of the Sampoong Group, decided to completely switch gears, and the blueprints were modified from an apartment complex to what would become one of the largest and most fancy department stores in South Korea. Although using a building of this size as a department store went against zoning regulations, Lee circumvented this by ordering the addition of a skating rink on an originally unplanned-for fifth floor.
Here's the thing about construction, you can't just decide to change the basic function of a building without heavily modifying the design itself, including reducing the size and number of support beams to clear the way for escalators, Woosung refused to make the changes, so Joon fired them and decided his own construction company would take over. This proved to be just one poor decision of many.
Building Design 101:
The Sampoong Department Store was created with a flat-slab design in mind, which essentially means that the building didn't have a steel frame or steel beams, either of which would have helped with load-bearing. Instead, each floor was supported by concrete columns. Sampoong also apparently used substandard steel reinforcing rods in the construction, thinner than those required by law.
After construction began, Joon changed his mind once again, turning the fifth floor skating rink into a gallery of restaurants heated by a system of under-floor hot-water pipes. Called ondol, this system is common in Korea. The weight of this system further increased the stress on the remaining columns.
Although the building was already much overburdened by these changes, perhaps the worst choice made was the addition of three air conditioning units on the fifth floor roof. Their combined 45-tonne weight was over four times more than the building was designed to handle.
To add to the growing list of problems, neighbors to the east complained about the noise from the air conditioning units. Management decided to move the units to the west side of the building, but rather than move them with cranes, which is the usual practice, the company used pullies and rollers to drag the units. Cracks now opened up on the roof, which only widened from the vibrations the air conditioners emitted every time they were powered on. One particular column beared the brunt of the weight, column 5E, which was directly beneath the air units on the fifth floor.
June 29th, 1995:
On the day of the collapse, two extraordinary things happened. Due to an alarming increase in the number and size of the cracks (some were nearly 10 cm, approximately 4 inches, wide) the decision was made to shut off the air conditioning units and block off customer access to the fifth floor. Structural engineers brought in to evaluate the cracks warned that total structural failure was imminent, but the store was unusually busy that afternoon. Not wanting to lose out on sales, the board refused to evacuate the building, although it was later discovered that most managers and executives were evacuated from the building at the time.
Hours later, at 5:50 p.m. Korean Standard time, cracking sounds reverberated throughout the building, causing store employees to finally begin evacuation procedures.
Unfortunately, it was too late. Moments later, the air conditioning units fell through the weakened fifth floor roof, causing the already strained support columns to disintegrate — resulting in each floor pancaking into the floor below it. This tragic event is still one of the most deadly building collapses in modern history.
More than 500 people perished in the collapse, and many more were injured.
Rescue Operations and Investigation:
More than 1,500 people were trapped in the rubble of what was once a shining beacon of South Korean prosperity. The rescue operation began almost immediately, but after two days, officials declared that all suvivors had already been rescued and there was simply no way additional survivors would be found still buried beneath the rubble. The status was changed from a rescue to a recovery operation.
Of course, and thankfully, they were wrong. Three survivors defied the odds. One was rescued after ten days, another after twelve days, and a 19-year-old was pulled from the rubble after sixteen days. The survivors noted that, tragically, some of the people buried beneath the remnants of the department store survived the collapse but drowned from the fire department's efforts to put out the flames caused by combusting cars.
The investigation into the tragedy revealed that, in addition to the not well thought out fifth floor addition, the badly placed air conditioning units, and reducing the diameter and number of support columns, the collapse was a perfect storm of terrible engineering. Had the developers stuck to the original plans, the stucture would have been twice as strong as it needed to be. Given all of the errors, it was amazing that the structure had had stood for 6 years.
Truth and Consequences:
Two members of the Sampoong group received prison sentences as a consequence of their negligence — Lee Joon and his son Lee Han-Sang (whose wife was among those trapped in the rubble). Various city officials were also incarcerated for accepting bribes to overlook the building's architectural flaws.
If you could say anything good came of this tragedy, it would probably be, with good reason, South Korean's demand for justice and accountability. After discovering the concrete used for the building was also substandard, and that every possible corner appeared to have been cut, Korean safety standards were revised. New inspections revealed that hundreds of other buildings in Seoul were also on the verge of collapsing. Only one building out of fifty was considered safe, one out of seven needed rebuilding from the ground up, and four out of five required major renovations.
Rest in peace to the 502 people who perished on June 29th, 1995.