Namchi, July 24 -- The bodies of all 25 workers have been retrieved from an NHPC hydropower project tunnel under construction, which had collapsed in Sikkim's Namchi district three days ago, officials said on Thursday. Three of them were recovered during the day, they said. The labourers were inside the NHPC Teesta Stage VI Hydropower Project tunnel that caved in following an explosion suspected to have been caused by methane gas shortly after 1 pm on Monday. The state government has constituted a high-level committee to investigate the cause and circumstances surrounding the tragic incident.P6...