South Korean government and corporate response teams are struggling to reach a hydropower plant construction site in Nepal where nine South Koreans remain unaccounted for amid concerns over further flooding, officials said Friday. The government's joint rapid response team arrived in Kathmandu late Thursday, while corporate response teams from Doosan Enerbility Co. and Korea South-East Power Co. arrived early Friday. The government and the companies have secured a total of six helicopters for search and rescue operations, but the aircraft have yet to receive flight approval from Nepalese authorities, according to ministry officials. "Helicopter travel is essential to reach the area, as roads and bridges have been washed away. But Nepalese authorities have restricted private helicopter operations over concerns about the possibility of additional flooding," a ministry oficial said. The nine missing people — six employees of Doosan and three of the power generation firm — were working at a construction site in Rasuwa district when a massive flash flood and mudslide struck the area Wedne