At the end of our trip we decided we had time to squeeze in one more route so went for what was a popular classic at the time. As we neared the top of the Nantillons Rognon a climber speed down past us. Even at this time the guide book stressed the need to move quickly throw this section because of the danger from falling seracs. It turned out that a climber had slipped and fallen to the base of the rognon. A number of climbers had descended to give aid and so we had decided that enough help was available to give support until the rescue team arrived and were about to head off on our route. At this point a section of serac broke away and swept down over the rognon and covered the injured climber, luckily not doing much damage to the climbers helping him . The climbers there spent a very short time pulling some of the snow and ice from the injured man and moved away from the danger zone. In what seemed a very short time a helicopter appeared and dropped three rescuers on the rognon. The descended and did a very efficient evacuation of the injured man, taking him down the glacier to where the helicopter could take them down.