This would not have happened if he would have unloaded the proper way ;
depress the loading gate and remove all the rounds in the mag. tube, you have one round left in the chamber which you unload by racking the lever , VOILA EMPTY SAFE FIREARM.
Do not forget , do this while pointing the firearm in a safe direction.
OBVIOUSLY THAT YOUNG FELLOW DID NOT POINT IT IN A SAFE DIRECTION AND WAS CARELESS, NEEDLESSLY ENDING SOME ONE'S LIFE.