Tuesday was the first time Waltz faced lawmakers since mistakenly adding a journalist to a private Signal chat used to discuss sensitive military plans.
The inspector general’s investigation focuses on how information about the March 15 airstrikes on Houthi targets in Yemen was shared on the messaging app.
The incident, in which the pilots were safely recovered, marks the third time since December that an F/A-18 assigned to the carrier Truman has been lost.