A six-month investigation into a cruise ship that capsized on the Yangtze River in June, killing 442 people, has uncovered problems in the shipping company’s daily management and local regulators’ supervision.

Although the State Council investigation team concluded that heavy storms caused the Eastern Star to capsize, it also found that the shipping company and local authorities had flaws in their daily management and suggested that 43 people be punished accordingly.

The incident was “an extraordinarily serious disaster caused by strong winds and heavy rains resulting from a squall line accompanied with a downburst, a rare type of severe convective weather,” according to the official report.