[Itaewon Disaster] "If about 100 adults weighing 65kg each push, pressure reaches 18 tons"... Bottleneck phenomenon in the sloped accident alley

Width about 4m, length about 45m, approximately 55 pyeong area
Crowds concentrated in narrow space increase scale of damage

Access to the site of the fatal accident in Itaewon, Yongsan-gu, Seoul, is being restricted on the 30th. Photo by Yonhap News

[Asia Economy Reporter Hwang Sumi] As investigations by the police and fire authorities continue regarding the Itaewon crowd crush disaster, experts analyze that the characteristics of the accident site exacerbated the scale of the damage.

The accident occurred on the night of the 29th in an alley next to the Hamilton Hotel in Itaewon-dong, Yongsan-gu, Seoul. This alley, which connects Itaewon Station Exit 1 to the World Food Street behind the Hamilton Hotel, is narrow enough for only 5 to 6 adults to pass through side by side. According to Yonhap News, the alley is about 4 meters wide and approximately 45 meters long. Calculated by area, it is only about 55 pyeong (approximately 182 square meters).

Moreover, this alley, which slopes uphill toward the World Food Street, is known to have a bottleneck structure where the width narrows as one goes up. The term "bottleneck," also called a traffic bottleneck, is used to describe traffic congestion caused by a sudden narrowing of a wide road, similar to the neck of a bottle.

At the time of the accident, a large crowd gathered all at once in this alley. Since it connects a bustling area and a main road, the flow of people coming down from the World Food Street above and those coming up from Itaewon Station below overlapped. Furthermore, one side of this path was the outer wall of the Hamilton Hotel, leaving people unable to move freely. Before the accident, people voluntarily practiced keeping to the right, but at some point, the crowd surged, causing confusion.

Experts explain that the narrow and sloped alley, combined with the large crowd, increased the scale of the damage. According to a YTN news special report, Professor Ham Eun-gu of the Department of Fire and Disaster Safety at Open Cyber University explained in an interview, "According to related studies, when about 100 adults weighing around 65 kg each are caught in a crowd, a force of approximately 18 tons is applied at the bottom," elaborating on the situation.

Professor Ham said, "Because the alley is sloped, when people at the back push, those in front usually resist by pushing back," adding, "As opposing forces act against each other, if people fall, the force continues to build up and overlap."

He further added, "If someone were run over by a vehicle, the load would be distributed across four wheels, which might prevent bones from breaking, but in this case, the concentrated load caused more severe damage." This explains that at the time of the accident, the load was not dispersed but concentrated in one area, forcing people to bear an enormous weight.

This content was produced with the assistance of AI translation services.