I don't know why anyone is shocked at this from N Korea. The dreaded Camp 22 has been doing all sorts of horrendous executions through human experimentation. Here is a quote from one of the former staff of the camp:
'I witnessed a whole family being tested on suffocating gas and dying in the gas chamber,' he said. 'The parents, son and and a daughter. The parents were vomiting and dying, but till the very last moment they tried to save kids by doing mouth-to-mouth breathing.'
LJ