The only concrete loss to the North and South has been superficial and caused by shallow depth of reinforcing. Whilst even small falling slivers of concrete is clearly a risk to people below, this is not a structural danger. In the past, treatment with rust preventer has solved the problem. The abseiling technicians who chipped off potential slivers failed to rust-treat the exposed rebar despite this being flagged to the managing agent - so it's a managing agent responsibility to rectify.