Hong Kong came to a standstill Sunday as Typhoon Mangkhut announced its arrival off China’s coast by tearing entire chunks off buildings and smashing windows. The typhoon—now the world’s strongest storm this year—packed wind gusts of up to 138 mph and sustained winds of 107 mph as it approached the city of 7 million people. More than 2.45 million people were relocated in southern China to escape the typhoon. Videos posted on social media showed chaos unfolding throughout the city, with streams of water shooting up out of residents’ toilets, roofs being blown away, and walls of water blanketing some areas. The typhoon, which the Hong Kong Observatory classified as a T10, the highest level possible, claimed dozens of lives in the Philippines before it headed for China. Philippine President Rodrigo Duterte told reporters that at least 40 people were killed after the typhoon flattened homes and triggered landslides.