The incident happened in the afternoon at Sea Walls at Avon Gorge and involved a drone. 2 teams were climbing on Morpheus and 1 team on sleep walk. 1 team (us) were waiting at the bottom to start the route once there was sufficient space. Two members of the public were watching the climbing and flying a drone. The drone had been seen previously flying at Main Wall. The drone was piloted to above the belay for pitch 3, circa 60m off the ground, around 10m from the wall. It was my partner on the ground who shouted ‘below’ as the only one who able to see the incident unfolding. The pilot then lost control of the drone and it flew straight into the wall narrowly missing the belayer at pitch 3 (this belayer was very clearly a novice and would not have had the skills required to rescue her leader should he have needed it). The drone, having lost two of its four propellers then fell again narrowly missing a leader on pitch 2 and her belayer. Finally it landed no further than 2m from where I was waiting. One of the leaders was hit by falling debris; no injuries were sustained. The two operating the drone appeared to be oblivious of the seriousness of what could have occurred if the drone had seriously injured any of the climbers.