Mines across South Africa shut down on Tuesday after flash flooding triggered the most severe power blackouts in more than a decade, threatening a key export sector in a further blow to the country’s already slowing economy. Heavy rains across parts of South Africa have submerged entire neighbourhoods, leading to evacuations and aggravating problems at state-owned utility Eskom, which has been struggling to keep the lights on since 2008. Harmony Gold, Impala Platinum and Sibanye-Stillwater all said they had been forced to cut production since Monday because of power shortages.