People take 20 seconds for granted. They have been chained by habituation to think that nothing significant will occur in that short period of time. However, only 20 seconds were needed for the grandeur, massive, pink structure to crumble into an ancient ruin. Only 20 seconds were needed for 937 people to be injured, 502 people to be killed, and 6 people to be missing. Only 20 seconds were needed to change an ordinary day into a living nightmare. Only 20 seconds were needed to give birth to the worst structural collapse in the history of modern architecture. The collapse of the Sampoong Department Store at 5:57PM on June 29, 1995, only needed 20 seconds.
Sampoong Department Store, which was located in the Seocho-gu district of Seoul, South Korea, began its construction in 1987. The pink mammoth was completed in late 1989 and was opened to the public on July 7, 1990. During the store’s five years of existence, some 40,000 people shopped daily at the complex. The building consisted of north and south wings which were connected to an atrium. Before its disintegration, the north wing was used as a shopping center while the south wing as a sports center. It was a nine-story building, with four basement floors and five floors above ground, having a gross floor area of 73,877 m2. It came as a runner-up to the main branch of Lotte Department Store in terms of retail store area. Not only that, Sampoong Department Store proved to be a great power by placing 7th in the nationwide department store yearly sales ranking.
So what caused this giant to collapse? What caused its once magnificent splendor to be blotted out from the minds of people, only to be remembered as a monument of terror? There are three reasons behind this case. First are the frequent changes in design without proper authorization. The retail store was originally planned to be a four-story office block. However, by the time the office block was almost completed, Lee Joon, chairman of the Sampoong Group, decided to change the building to a five-story department store. The conversion required a number of support columns to be removed for the installation of escalators on each floor. Also, the extension of the fifth floor, which was used as a restaurant that included heavy equipment, resulted in the load far exceeding the allowable limit. Furthermore, on October 1994, unneeded structural changes were done in the first basement floor to increase the store’s instability. Second is the mishandling of structural calculation. Eight among the 20 columns supporting the fourth and fifth floors were supposed to have a diameter of 800mm with 16 steel reinforcement beams embedded. However, those eight columns only had a diameter of 600mm with eight steel reinforcement beams. The distance between the columns and the concrete surface of the upper slab was reduced as well from 15cm to 9cm. Even the materials used for construction were found to be problematic. The strength of the concrete used was weaker by 110kg/cm2 than the standard concrete. These faulty constructions produced slimmer supports which made the already unstable building more prone to collapse. Third is the installation of the air conditioning units on the roof. Due to the noise complaints from neighbors on the east side of the building in 1993, the units were moved to the roof. Instead of using professionals, the air conditioning units were simply put on rollers and dragged across the roof causing cracks to appear. These cracks were later widened by the vibration from air conditioning and were radiated towards the frail columns. This served as the last straw for the destined 20-second collapse of the Sampoong Department Store to occur.
The aftermath of the Sampoong disaster was tremendous. Aside from the fact that it was South Korea’s worst peacetime disaster with 1,445 people harmed, the collapse resulted in about US$216 million worth of property damage. Twenty-five Sampoong Department officials who were related to the collapse were sentenced to prison and Chairman Lee Joon was no exception to this predicament. He was found guilty of criminal negligence and was sentenced to prison for 10 and a half years. The collapse of the Sampoong Department Store, however, was not only about tragedies, for like the proverbial cloud, it had a silver lining. When the South Korean government realized the drastic impact of faulty constructions, they conducted a nationwide building investigation, where only 2 percent of the buildings were deemed safe, 84 percent of the buildings needed repair and 14 percent of the skyscrapers had to be rebuilt. This led to a stricter implementation of the construction permit system and building codes. Like the sinking of the Titanic which gave rise to new naval laws, the Sampoong disaster gave birth to new construction laws resulting in a sturdier generation of buildings in South Korea.
Yoon, Hyung Tong