A Nepali tour operator says he fears that 15 Australians trekking with his company in a valley ravaged by flash flooding have died.Sagar Pandey, the founder and chief executive of Himalayan Glacier Trekking, said he had lost all contact with his tour group of 47 people, which included 15 Australians.The missing Australians ranged in age from 11 to 64 and the group was believed to include two families of four from New South Wales.He had since flown by helicopter over the Rasuwa area, where the tour was staying, and said he had little hope they survived.“To be honest … you would think there was no human civilisation there at all.“The flash flood swept away everything, everything, you couldn’t see any human creations.“Still, I have a hope, but like 1%; the rest I don’t have a hope, they are missing and missing and missing.”Pandey, who is also the president of the Trekking Agencies’ Association of Nepal, said he had been coordinating with other local tour groups, which had also lost contact with their guides in the area.Among those groups were operators who had arranged tours for Australians, he said.skip past newsletter promotionafter newsletter promotionPandey said his missing group included tourists from the UK, US, Canada and Singapore and his guides.They had made their way to the valley after a drive of about seven hours from Kathmandu, and had been expected to head towards the border with China at about 8.30am on the day the flood struck.Pandey said that on his helicopter flight he noticed about 100 people on higher ground, who he believed were local people who narrowly escaped the carnage.