Sushil Koirala, a former Nepalese prime minister and leader of the nation’s largest political party, has died in Kathmandu. He was 78.His doctor, Karbir Nath Yogi, said Tuesday that Koirala died due to complications from pneumonia and respiratory failure.Koirala was a key figure in the adoption of Nepal’s new constitution last September. After ethnic Madhesis later blocked border points with India and imposed a general strike in southern Nepal to protest against the constitution, Koirala attempted to resolve the issue by negotiating with the protesters. -