The search and rescue team right the capsized cruise ship in the Yangtze River in this June 5, 2015 file photo. It was heavy storms during freak weather that caused a cruise ship to capsize and kill 442 people, an official investigation has declared. [Photo provided to chinadaily.com.cn]

BEIJING - It was heavy storms during freak weather that caused a cruise ship on the Yangtze River to capsize in June and kill 442 people, an official investigation has declared.

A State Council investigation team concluded that the incident was "an extraordinarily serious disaster" caused by strong winds and heavy rains resulting from a squall line accompanied by a downburst, a very rare weather phenomenon, according to the official statement released Wednesday.