This evening, via Twitter:

Vivian Salama @vmsalama
North Korea executed Kim Hyok Chol, its special envoy to the United States, and foreign ministry officials who carried out working-level negotiations for the second US-North Korea summit in February, holding them responsible for its collapse.
[….]
6:14 PM – 30 May 2019

That’s Juche for you.

Well, Kim Jong Un certainly has a dynamic error correction process.