 Past the first barrier and with increasing momentum, Macdonald's force crossed abandoned defences at Kangma a week later, and on 9 April attempted to pass through Red Idol Gorge, which had been fortified to prevent passage.Macdonald ordered his Gurkha troops to scale the steep hillsides of the gorge and drive out the Tibetan forces ensconced high on their cliffs.This they began, but soon were lost in a furious blizzard, which stopped all communications with the Gurkha force.