Seoul, South Korea (CNN) -- Massive downpours in South Korea -- the heaviest rains in a century -- are blamed for 51 deaths, the country's Central Disaster Relief Agency reported Friday. One person is also missing, the agency said. Conditions improved Friday morning when the Seoul Gimpo International Airport reported light rain and mist with overcast skies, according to the U.S. National Weather Service's international weather conditions website. On Thursday, rain fell in some areas around Seoul at a rate of 50 millimeters an hour (two inches an hour). The most recent numbers released by the Central Disaster Relief Agency indicated that much of the death toll comes from landslides triggered by the rain. In Chuncheon, 13 people were killed by landslides, while 16 were killed by the same phenomenon in Seoul. Another 18 died in Gyeonggi province. Five neighborhoods on the outskirts of Seoul had been under evacuation orders Thursday. But officials were able to restore ele...