I think 800KG is exceedingly rare, and also the upper limit of what a climber can tolerate even if their protection (the camming device) holds. It does happen w

I think 800KG is exceedingly rare, and also the upper limit of what a climber can tolerate even if their protection (the camming device) holds. It does happen with massive lead falls, especially when not much rope has been paid out. 1000 KG is likely to cause injury. And of course, the cams are typically rated from 600KG to 1600KG of force, depending on manufacturer, size, and material. But it's rare for them to experience these loads. Even with smaller falls though, say 200-300 KG of force, they do occasionally break the rock they're set in, or cause the rock to 'flex', causing it to come out (this is more common with a type of feature called a 'flake', which is a semi-detached piece of rock, rather than a typical crack which is unlikely to move). Ideally, you have more protection beneath the one you placed. Then if one piece blows, you'll fall a little bit further to the next one, which is hopefully placed in better rock.