July 10, 2021 (Mainichi Japan) This photo taken from a Kyodo News helicopter on July 6, 2021, shows the site of a huge mudslide triggered by torrential rain in the Shizuoka Prefecture hot spring resort city of Atami, central Japan, with the arrow pointing to the approximate starting point. (Kyodo) SHIZUOKA, Japan (Kyodo) -- As search efforts continue for 21 missing people following a large mudslide that hit a spa resort town in central Japan last weekend, experts and local authorities suspect improper accumulation of soil led to the fatal calamity. Local authorities say an estimated 54,000 cubic meters of soil which had been brought to a mountainside by a real estate management firm exacerbated the massive mudslide on July 3 in Atami, Shizuoka Prefecture, resulting in the death of nine people.