Crowds have been gathering from early hours around Gwanghwamun Square in Seoul on the 21st, where group BTS is holding its comeback concert.
According to Seoul's real-time urban data, as of 1 p.m. that day, the floating population around the venue (Gyeongbokgung to City Hall) was estimated at 24,000 to 26,000, up 77% from three hours earlier. The city expected the floating population to exceed 30,000 around 3 p.m.
The share of nonresident population (70.1%) was more than 40 percentage points higher than the resident population (29.9%). Resident population refers to people who stayed at least four hours a day for at least 10 days in the previous month. This means many people came from outside the city for the BTS concert.
By age, those in their 20s made up the largest share at 21.6%, followed by 60 and older at 20.3%, those in their 30s at 20%, and those in their 40s at 17.1%. By gender, the shares of men and women were at nearly the same level.
As crowds swelled, lines for security checks formed at each gate. Entry and exit to the venue that day are allowed only through 31 gates.
Police and other authorities are guiding people to keep to the right to manage the crowd. Requests to people who stop to take photos to "please keep moving" have been constant.
Traffic controls are also set to ramp up. Gwanghwamun Station on Seoul Subway Line 5 will be bypassed without stopping from 2 p.m., and City Hall Station on Lines 1 and 2 and Gyeongbokgung Station on Line 3 will be bypassed from 3 p.m.
Sejong-daero has been closed to traffic since the previous night, and Sajik-ro and Yulgok-ro will be closed from 4 p.m. to 11 p.m. that day.