On June 29, 1995, the Sampoong Department Store (Korean: 삼풍백화점; Hanja: 三豐百貨店) in Seoul, South Korea, collapsed due to a structural failure.

This involved cutting away a number of support columns to install escalators and the addition of a fifth floor (originally meant as a roller skating rink but later changed to a food court).

The fifth-story restaurant floor had a built-in heating system known as an ondol, with hot water pipes passing through a 1.2-metre-thick (4 ft) concrete base.

These units generated high noise levels when operating, leading to complaints from adjacent property owners; in an attempt to remedy the situation, they were dragged across the roof to a new location in 1993, resulting in cracking.

On the morning of June 29, the number of cracks in the area increased dramatically, prompting store management to close parts of the top floor.

Five hours before the collapse, the first of several loud bangs was heard emanating from the top floors, as the vibration of the air conditioning caused the cracks in the slabs to widen further.

However, Seoul's mayor, Choi Pyong-yol, announced the rescue would be called off due to concerns that the unstable remains of the store would collapse.

[7] After massive protests, especially from friends and relatives of those still missing, Choi and officials agreed to continue looking for survivors, with the remains of the store being steadied by guy cables.

At one point, Korea Telecom was transmitting a signal every half hour, designed to trigger cellphones or pagers that trapped survivors might be carrying.

[10] The investigation of the collapse was headed by Professor Chung Lan (Korean: 정란, Hanja: 鄭鑾) of Dankook University's engineering school.

However, the fires in the rubble were from burning automotive gasoline coming from crushed cars parked in the underground garage, and a gas explosion would have been significantly larger.

However, the fact the building collapsed downward, with little debris thrown outward, ruled out a significant explosion, according to South Korean and American experts.

Worse still, the number of steel reinforcement bars embedded into the concrete was 8, not the required 16, which gave the building only half its needed strength.

On the day of the collapse, although the units were shut off, it was too late, the structure had suffered irreversible damage, and the fifth floor slab around column 5E finally gave way.

During his interrogation with Professor Chung, Lee Joon sparked further controversy by saying that his main concern was that the collapse of the store not only harmed the customers, but also inflicted great financial damage to his company.

[13] Lee Joon died on October 4, 2003, months after his release from prison, of complications from diabetes, high blood pressure and kidney disease.

[14] City official Lee Chung-Woo, who was a chief administrator of the area where the store was located, was sentenced to three years in jail for bribery.

[15] Hwang Chol-Min, a former chief for the area, was found guilty of accepting a ₩12 million bribe from Lee Joon, and was sentenced to 10 years in prison.

[21][22] The disaster spurred significant reforms in South Korea's construction industry, leading to comprehensive changes in building standards and legislation to prevent future tragedies.

The new laws and regulations were designed to enhance building safety, improve structural integrity, and ensure greater accountability and transparency in the construction industry.

These measures aimed to prevent future disasters and restore public confidence in the safety of South Korea's buildings and infrastructure.

The twelve-meter high marble memorial was designed by Ewha Womans University professor and sculptor Kim Bong-gu, and funded by the Sampoong Group as compensation to the victims.