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.

A motorcyclist who fell into a massive sinkhole that opened up on a street in Seoul was found dead after an overnight search.

A fatal sinkhole that opened in the middle of a busy street in Seoul on Monday is raising new alarms about the growing risk of ground collapses in South Korea’s ever-developing urban centers. As cities across the country expand underground infrastructure — from subways to drainage systems — concerns are growing over whether safety regulations are keeping pace.