South Korea’s Ministry of Interior and Safety said three of the dead were trapped in a submerged basement floor. The ministry said nine others were injured and at least seven were still missing.
Since midnight Monday local time, parts of Seoul have seen a total of 422 mm (16 inches) of rain, prompting authorities to raise the emergency alert level above level 3. The city has recorded 141.5 mm (5.57 inches) of rain per hour – the highest Rate since authorities began keeping records.
Pictures from around the city show severe flooding, with people wading across roads up to their thighs into the water.
Although the floodwaters had largely receded by Tuesday morning, cars and buses were left strewn across roads and sidewalks, blocking morning traffic.
In some parts of Seoul, it has bolstered drains and sent water to streets and subway stations, according to Seoul Metro. A number of subway stations were closed due to the flooding, with lines temporarily suspended Monday night. As of Tuesday morning, authorities were still working on reopening stations.
Several areas south of the Han River were hardest hit, including the affluent modern district of Gangnam where some buildings and shops were flooded and electricity was lost.
About 800 residents were either evacuated to schools and gyms or voluntarily sought shelter in local community centers as the flooding affected more than 700 homes and shops, according to authorities.
He also noted the need to review the country’s disaster management system, as extreme weather is expected to become increasingly common due to the climate crisis.
Several countries across East Asia are now seeing more intense daily rain, as the summer monsoons are expected to get stronger and more unpredictable as the Earth warms, according to the Intergovernmental Panel on Climate Change.
Heavy rain is expected to continue on Tuesday, with an average of up to 100 mm (3.9 inches) of rain per hour in some areas, according to the country’s meteorological department.
Additional reporting by Jake Kwon of CNN and Reuters.