Dehradun/ New Delhi, Aug. 15 -- Seven workers were confirmed dead and three remained trapped inside a flooded, under-construction hydropower tunnel in Chamoli late on Friday, more than 24 hours after a suspected aquifer burst sent a surge of water and debris rushing through the passage - the latest in a string of accidents at Himalayan hydroelectric projects this monsoon. Rescue teams from the NDRF, SDRF, Army, ITBP, CISF, fire service and state police, backed by heavy pumps and specialist equipment, spent Friday wading through water that was chest-deep in places along a roughly 1.2-km flooded stretch of the tail-race tunnel (TRT) at Tehri Hydro Development Corporation (THDC) India's 444 MW Vishnugad-Pipalkoti project, searching for the three missing men. Officials said continuous water inflow, low visibility and the risk of further collapse were slowing progress. Of the 22 workers on shift when the incident occurred around 7pm on Thursday, 19 have been brought out - seven of them declared dead at the district hospital in Gopeshwar and 12 admitted with injuries, including one referred to the Base Hospital at Srinagar. The three still missing are Lucas Topno from Jharkhand and Chetan Poyam and Devnath, both from Chhattisgarh. Ajay Verma, executive director of the Vishnugad-Pipalkoti Hydro Electric Project (VPHEP), said preliminary assessment pointed to a rain-saturated aquifer that ruptured through the roof of the 3-km tunnel about 1.44 km from the entrance. Thursday's incident is the ninth accident or weather-linked disaster to hit a hydropower or dam project in the Himalayan belt since June 24....