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Why did so many people die during the Japan earthquake and tsunami of 2011?

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earthquake damage, Honshu, Japan, 2011 — Japan earthquake and tsunami of 2011 Aerial view of damage to a portion of the northeastern coast of Honshu, Japan, following the offshore earthquake and resultant tsunami there on March 11, 2011.

The vast majority of deaths during the 2011 disaster in Japan were caused by drowning due to the powerful tsunami waves that struck the Pacific coastline.12

Following a magnitude 9.0 earthquake, these waves inundated low-lying coastal cities, towns, and farmland, reaching several miles inland in many locations. The water swept away enormous quantities of debris, including houses, vehicles, and infrastructure, which contributed to the widespread destruction and loss of life.13

While the earthquake itself caused significant damage—including fires, building collapses, and the disruption of essential services—the tsunami was responsible for the overwhelming majority of the fatalities. Notably, more than half of the victims were age 65 or older. The official total for those confirmed dead or listed as missing was approximately 18,500, with the prefectures of Miyagi, Iwate, and Fukushima suffering the most severe losses.132