Former Prime Minister of Nepal and Nepali Congress President Sushil Koirala passed away due to Pneumonia at his residence early today. He was 79. Koirala, who was elected Prime Minister of Nepal on February 10, 2014, died at his residence in Maharajgunj in the outskirt of capital Kathmandu at 12.50 am (local time), Nepali Congress general secretary Prakash Man Singh told PTI. He had returned from the US after undergoing a successful treatment for the lung cancer and is credited with promulgating the new constitution of Nepal in September last year. Koirala was suffering from Chronic Obstructive Pulmonary Disease (COPD) and he succumbed to the disease. His body will be taken to party's central office at sanepa, Kathmandu and kept there for last tributes from party cadres and others, Singh said. Born in Banaras, India, Koirala entered politics in 1954 and was in political exile in India for 16 years following the royal takeover of 1960. He also spent three years in Indian prisons for his involvement in a plane hijacking in 1973.