The top Democrat and Republican on the Senate Armed Services Committee have jointly called on the Department of Defense’s inspector general to conduct an inquiry into the Trump administration’s Signal usage.

More than a dozen senior administration officials were involved in a group chat on Signal in which they discussed the merits of starting a new military campaign against the Yemen-based Houthis. They continued to use the chat as the U.S. military began those operations, but unbeknownst to them, Atlantic Editor-in-Chief Jeffrey Goldberg had been added to the group chat from the outset.