Sudden and extreme weather conditions capsized a Yangtze River cruiser and left 442 people dead, a central government investigation has found.

The investigation, led by the State Administration of Work Safety and 10 other government departments, also called for an early warning system to be set up for extreme weather on rivers.

Strong winds and heavy rain resulting from a squall line sank the Eastern Star, according to a statement published on the watchdog's website on Wednesday.

The river cruiser, carrying 454 people, capsized en route from Nanjing to Chongqing on the night of June 1, and only 12 people on board survived.

A squall line refers to a line of strong to severe thunderstorms with strong, gusty winds. It is usually associated with sharp wind shear, including sudden, marked shifts in wind direction and speed, according to the Office of the Federal Coordinator for Meteorology of the United States.

The vessel's captain, Zhang Shunwen, tried to keep the ship stable, but the winds forced it back and the captain eventually lost control. It took just a minute for the vessel to flip over, the report said.

The inquiry recommended that Zhang, who survived, have his captaincy qualifications cancelled and that he be investigated for criminal behavior.

Xu Xiangde, a researcher at the Chinese Academy of Meteorological Sciences and a member of the investigation team, said meteorological authorities had been unable to forecast the squall line due to limited radar coverage.

The inquiry report said, "The country should increase the coverage of weather radar systems and the network of automatic meteorological stations along the Yangtze River to ensure the safety of river transportation."

The inquiry also found that the Eastern Star had undergone three renovations in 1997, 2008 and this year to increase passenger capacity and to upgrade the cabins.

After the three renovations, the cruiser's capacity to withstand strong winds could still meet national standards, yet its ability to withstand such winds fell after each renovation, the report said.

It also found a number of malpractices and supervisory failures by government departments and the cruise company. It said 45 people should be held responsible for the incident, and suggested punishment for 43 of them.

xuwei@chinadaily.com.cn