Check out the crazy moment these mountain climbers were left in panic after several boulders fell away and crashed down the mountain side. Brett Booth was out climbing with his friend, Matthew, in Cadair Idris, Wales, when they were both left in a panic after hearing falling rocks above them. Stuck on the side of the cliff, the friends heard a range of shouts and crashes before the boulders came tumbling down the mountain at high speed, smashing into everything in their path. After the boulders passed the pair, they were able to shout down to the climbers below to warn them. Fortunately, Brett says that no one was hurt.