The 50-odd members of the rescue team have been trying to dredge a passage to the stranded men but have made little headway into the 1.6-km Tapovan tunnel. “We have marked a spot 70m inside the main tunnel, where we will start digging. About 12m below is a silt flushing tunnel (which carries sediment-laden water out). This is connected to the main tunnel at a point beyond the slush and debris,” ITBP spokesperson said. Beside this, an air recce led by a team of ITBP officials was conducted by a helicopter to take the stock of probable site from where glacial burst was reported that had caused flash floods in Rishi and Dhauli Ganga on February 7.