I am a short female climber and have been climbing over 20 years (indoors and outdoors; mountaineering, trad, sport and bouldering). I was bouldering on a problem graded well within my capability. The climbing centre often sets reachy bouldering problems and unlike another local wall it does not indicate 'low reach' routes (i.e. routes that go at the grade for climbers who are short). I had easily climbed all except the last move. At the final move my left foot was on a bad hold, left hand just touching the final hold, right foot at the top end of a volume and I was unable to reach the final hold with my right hand. I don't recall how I fell, but I assume my right foot slipped off the volume. I only remember landing on my neck with a huge jolt as my head snapped forwards. The next thing I saw I was lying on my back with my right arm facing the climb and my legs facing 90 degrees to the left of it. I lay on the ground for a while, then got up. By the time I had walked to the climbing wall reception I knew I was concussed and asked for a first aider. They recorded the incident and advised me to seek medical help. My partner came with me to A&E by car. I was then immobilised in a room in a neck brace for MRI scans of my brain and neck. I was discharged several hours later with a concussion but no fracture to the neck. The NHS staff were brilliant. I feel lucky to have walked away, but I do not know if the concussion will cause ongoing problems.
I was working on a session at an indoor wall. Whilst instructing a group of children I saw a person set off leading. The belayer had a lot of slack out and I recall thinking they would struggle to take in the slakc quickly once the first bolt was clipped. The belayer did struggle but much more than expected. After a few seconds they hadn't taken in any slack and seemed to be fiddling with something. I couldn't see but expected they had put a grigri on the rope upside down and were taking it off to sort it out. The climber was still going. I was backing up a child and had the climber lowered off as quickly and safely as possible. I rushed over to the struggling belayer who was just doing up the screw gate again. The climber had been at least at 4th not attached to the rope at all. They had no idea they had been off belay.