Top executives at two Chinese coal mines were being handed over to prosecutors and will likely face criminal charges for their roles in accidents that drowned 181 miners, the Xinhua News Agency reported Tuesday.

Wrapping up an investigation into one of the worst accidents in more than a half-century of Communist rule, safety investigators referred six people to prosecutors, among them the heads of the Minggong Coal Mine and the Huayuan Mining Co. in eastern Shandong province, Xinhua said.

The investigative panel, comprised of provincial safety and other officials, concluded that the Aug. 17, 2007, flood was brought about by torrential rains that caused a river to breach its banks, but that the mines were poorly prepared for an accident.

The flooding "exposed prominent problems in workplace safety and accident prevention among local governments, agencies and enterprises," said the Xinhua report.

With China reliant on coal for about 70 percent of its booming economy's energy needs, Beijing has been trying to improve safety in its accident-plagued mines. However, the effort has been frustrated by lax enforcement, safety inspectors who lack power and corruption between local officials and profitable mines, the Associated Press reports.

The watchdog State Administration of Work Safety has turned to publicizing investigations into accidents to try to shame officials into compliance and shore up public confidence, according to AP.