What We're Following This Afternoon

Criticism of North Korea grows: Presidential candidates and the UN secretary-general are among those who have expressed concern over Pyongyang’s claim that it has tested a hydrogen bomb. Nuclear and regional experts are skeptical about the North’s claim and its broader significance.

A criminal investigation of Chipotle: Federal authorities have launched a criminal investigation of the fast-casual chain in connection with a norovirus incident last August in Simi Valley, California, Chipotle said today in an SEC filing. It said it was cooperating fully with the investigation.

RIP, Pierre Boulez: The French composer died Tuesday at his home in Baden-Baden, Germany. He was 90 years old. Here’s an appreciation of him in the September 1995 issue of The Atlantic.

Our headlines from the morning are here.