We were a group of 4 with an instructor on an ice climbing multi-pitch route, specifically an artificial waterfall. The instructor was very familiar with the area and has been leading the group for the last 4 days so I'd say he chose the route within the skill level of the group. The weather was cold but clear.

The lead climber was making her way up when she lost her balance and fell head first backwards. Her crampons clipped the back of the belayer on her way down and she landed face forward on her thighs. She later found out that she came to a halt only when the belayer found and pulled the rope - he was apparently rearranging the ropes so took his break hand off the rope when she fell. As a result, she fell a good 3 person's height before her fall was arrested and believed that her fall was slowed down on a more gradual section of the waterfall enabling him to catch the rope, before it fell off again.