Summary of information reported by those at the scene:
At least 3 experienced members of the club had climbed the route without issue. The route was one tier up from the bottom of the quarry. On ascending, the climber shouted down to warn the belayer and those below of rockfall. A large rock the size of a beach ball fell and hit the ground next to the belayer. The rock ricocheted from the ground and hit the belayed on the right side of their trunk. The rock rolled off the tier and to the bottom level of the quarry. Climbers shouted to warn those below. No one was injured on the bottom tier.
The climber on the route was brought to a safe position and the belayer was released from the belay. People attended to the injured belayer by making them as comfortable as possible. The emergency services (and mountain rescue) were called and the injured person was taken to hospital where they required medical intervention.