They aren't that well trained either. And most well trained people will never clean and jerk 300+lbs. Even if every single kid who tried a 300lbs+ clean and jerk died from it on the spot, that still wouldn't make enough of a dent to make lifting a high risk sport.

The thing worth keeping in mind that people forget when questioning whether kids should lift, is that kids lift, or try to lift large percentages of their body weight to failure all the time during normal play. They have a training capacity and recovery ability that makes me insanely jealous as someone who's turned 40.

If lifting the weights they are physically able to is dangerous for them, then so is a lot of their regular playing.