Sentence:  This chapter uses case studies along with a new data set focused on Kobe's nine wards after the city's 1995 <WSD>megadisaster</WSD>, the earthquake known in Japanese as the Hanshin Awaji Daishinsai (the Great Hanshin—Awaji Earthquake), … 
Meaning of the word marked with <WSD> tags:  An unexpected natural or man-made catastrophe of exceptional magnitude, causing unusually severe or unprecedented damage.