In the early 1970s, the Intelligence Agency of the State Oceanic Administration (SOA) had researched tsunami and earthquake history. Past earthquakes in China, such as the 1975 Haicheng earthquake, the 1976 Tangshan earthquake, and several large earthquakes that occurred in the Bohai Sea, did not cause any noticeable tsunamis. This has led to the spread of claims in Mainland China that there have been no destructive earthquake-generated tsunamis in China. According to research on Chinese and regional tsunami history, however, China is considered to have frequent earthquake-generated tsunamis. China has the most deaths caused by tsunamis out of any country, accounting for one-third of all global tsunami-caused deaths.