The sinkhole suddenly appeared near an intersection in Seoul's Gangdong district around 6:30 p.m. local time on Monday.

Sinkholes are especially common during two critical seasons: spring, when frozen ground thaws, and summer, when heavy rains soak and erode underground soil. Government data shows that, since 2018, nearly 76 per cent of all sinkhole incidents occurred during these two periods alone — 371 cases in spring and 647 in summer.